US 7893655

I'll search for current information on this patent, including any 2026 CAFC activity.

Let me check for any 2026 Federal Circuit activity involving this patent or its owner.

Let me dig into the IPR outcome for this specific patent, since the record shows an IPR certificate issued.

US Patent 7,893,655 — Summary

Important caveat up front: I searched for UPSTO and CAFC 2026 docket activity specifically tied to patent 7,893,655. I found no 2026 CAFC appeal, docket entry, or briefing naming this patent. The litigation/PTAB history I could confirm all dates to 2016–2019. I therefore cannot report any 2026 appellate activity — that absence may simply reflect that none exists, or that my searches did not surface it. Treat the 2026 CAFC portion as "no evidence found," not as a definitive negative.

Bibliographic data (per the granted patent record)

Note the priority chain: this patent is a continuation of US 11/299,701 (US 7,701,173 B2), and it in turn has a child continuation, US 13/004,175 (US 7,965,058 B2). EP 1 798 835 B1 ("Charger and power supply for mobile devices") is in the same family.

Abstract (as issued)

A USB-compliant charging and power supply circuit includes switch-mode battery charging circuitry for receiving power from an external power source and for supplying output power through an output node to an electronic system of an electronic communication device and a battery. Battery isolation circuitry includes a semiconductor switch connecting the output node to the battery. The battery isolation circuitry senses voltage at the output node and variably restricts current to the battery when the voltage is below a minimum voltage value by operationally controlling the semiconductor switch as current passes through it. During variable current restriction the electronic system is supplied required power with the battery being supplied any additional available power.

Plain-language overview of the independent claims

The patent as displayed has three independent claims — 1 (method), 3 (circuit), 8 (device) — plus dependents 2, 4–7, 9–11.

Claim 1 — Power-management method. A method of allocating power between a rechargeable battery and an electronic system that has a power input and multiple modes of operation. The method: (a) generates output power; (b) receives a reference voltage from the electronic system; (c) determines, based on that reference voltage, the minimum voltage needed at a node directly connected to the system's power input; (d) senses that the node voltage has dropped below that minimum; and (e) in response, restricts current from the output power going to the battery, thereby increasing power allocated to the electronic system. In plain terms: watch the system's supply rail; when the battery is dragging it down, throttle battery charging so the system is never starved.

Claim 3 — USB-compliant charging and power supply circuit. A circuit with switch-mode battery charging circuitry that receives external power and supplies output power through an output node to both the electronic system and the battery (via a switch). The circuitry has an integrated circuit cooperating with an inductor so the output current exceeds the external input current (a boost of current via step-down switching — the efficiency point emphasized in the specification). Battery isolation circuitry receives a reference voltage from the electronic system, determines the required minimum output-node voltage from that reference, senses when the node voltage falls below the minimum, and controls the switch to restrict battery current, increasing power to the system.

Claim 8 — Electronic communication device. The apparatus counterpart of claim 3: a device housing containing a rechargeable battery, an electronic system, and the charging/power-supply circuit described above (switch-mode charger IC + inductor producing higher output current; battery isolation circuitry that takes a reference voltage from the electronic system, establishes a minimum output-node voltage, senses an undervoltage condition, and restricts battery current accordingly).

Dependent claims add: deriving output power from an external source such that it has higher current/lower voltage (claim 2); switch-mode power supply circuitry that converts battery power back through the same inductor/output node to the system (claims 4, 6, 7, 9); feedback of the node voltage to the IC for adjustment (claim 5); the switch being a semiconductor switch (claim 10); and circuitry that turns the switch off when charging is disabled (claim 11).

Notable engineering features from the specification: the design uses two switch-mode ICs — a Li-ion charge-management IC (TI bq24105/bq24115 example) and a DC-DC converter (TI TPS62000 example) — sharing a single inductor (4.7 µH) and output node V_SYS; the battery isolation stage uses an op-amp driving a p-channel FET operating in the triode region as a variable resistor; and FIG. 3 adds a variable reference (voltage source 274) so V_SYS can be dynamically set to the highest required power rail for the current mode (e.g., sleep vs. RF-active).

Litigation and PTAB history (confirmed records)

• District court: FISI asserted the '655 patent against multiple handset vendors in the Eastern District of Texas, including Samsung (2:17-cv-00145, filed Feb. 21, 2017), ZTE, Huawei (2:16-cv-01424), and LG (2:16-cv-01425). Several later campaigns followed (Apple, Belkin, Lenovo, TCT Mobile, Anker, etc.).
• IPR2018-00425 (Petitioner variously identified as ZTE USA/Samsung; filed Jan. 5, 2018) — instituted July 6, 2018; Final Written Decision July 2, 2019, challenging claims 1–11. The Google Patents record shows an IPR certificate (K1) issued October 24, 2019 for this proceeding, which indicates claims were cancelled or amended as a result.
• IPR2018-00479 (Huawei Device) — filed Jan. 12, 2018; terminated by settlement per the Google Patents family record.
• IPR2018-00683 (LG Electronics) — filed Feb. 22, 2018; settlement.
• IPR2018-01076 (ZTE) — filed May 14, 2018; institution denied (procedural), Dec. 3, 2018.
• The ZTE IPR also produced a notable § 312(a)(2)/§ 315(b) real-party-in-interest ruling (IPR2018-00425, Paper 34, Feb. 6, 2019), allowing ZTE to retroactively name ZTE (TX) Inc. as an RPI to avoid a time bar.

Uncertainty flag: The 11 claims shown in the patent text I have (with the "receive a reference voltage from said electronic system" and "having an integrated circuit and an inductor" limitations on independent claims) differ from the claim language summarized in the patent's own "Description of Example Embodiments" section, which recites "determining a minimum voltage needed … with reference to which of the modes of operation the electronic system is currently in." That discrepancy, together with the October 24, 2019 IPR certificate, strongly suggests the displayed claims are post-IPR amended/substitute claims. I could not, within my available searches, retrieve the actual Final Written Decision text or the certificate's specific disposition (e.g., which claims were cancelled vs. amended) for the '655 patent, so I would not represent the exact scope of the surviving claims as certain. Likewise, any assertion that claims or parties won/lost at the Federal Circuit should be verified directly against the PTAB and CAFC dockets.

I'll research the litigation history for US patent 7,893,655 using the sources you mentioned.

I found substantial litigation data. Let me dig deeper into the specific district court cases and outcomes.

Litigation Involving U.S. Patent No. 7,893,655 ("the '655 patent")

I searched the Unified Patents litigation/PTAB portal, PACER-derived dockets (CourtListener/RECAP), Justia, Docket Alarm, the USPTO/PTAB filings surfaced in the patent's own family data, and law‑firm/NPE commentary. There is substantial known litigation involving the '655 patent. The patent was asserted by Fundamental Innovation Systems International LLC ("FISI") (current owner, an NPE that acquired the portfolio from BlackBerry/RIM in Nov. 2015) against several mobile-device and charger manufacturers, and was separately challenged in four AIA inter partes reviews at the PTAB.

A preliminary note on the asset: the '655 patent (application 12/716,535) is a continuation of the '173 patent (U.S. 7,701,173), and its child continuation is U.S. 7,965,058 ('058). The '655 is generally grouped with the '319 (Veselic 2003) and '173 families (the FISI "battery charging / power management" patents), while the Fischer patents ('936/'111/'586/'766/'550) were the focus of later campaigns. The '655 itself should not be confused with its sibling patents.

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1. District Court Litigation

Sources: the patent's own Google Patents litigation links (2:16‑cv‑01424, 2:16‑cv‑01425, 2:17‑cv‑00145); FISI's Updated Notice in IPR2018-00479; the PTAB IPR2018-00425 decision (Mintz copy) describing the Samsung and ZTE service of complaints; and the N.D. Tex. docket 3:17‑cv‑01827 (CourtListener) showing the Jan. 3, 2020 dismissal with prejudice.

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2. PTAB Inter Partes Review Proceedings (contested validity of the '655)

These four proceedings are the ones listed in the '655 patent's own Google Patents "Family has litigation" record, with the statuses: IPR2018‑00683 (Settlement), IPR2018‑00425 (Final Written Decision), IPR2018‑01076 (Not Instituted – Procedural), and IPR2018‑00479 (Settlement).

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3. Federal Circuit (CAFC)

I found no CAFC appeal specific to the '655 patent. The IPR2018-00425 Final Written Decision and the district-court dispositions all resolved by settlement or were not appealed to the Federal Circuit on the '655 record that I located. (ZTE's related Federal Circuit activity appearing in searches involved patents held by InterDigital, not the '655 — do not conflate those.)

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4. Caveats and limits of this answer

• The later FISI campaigns (2020–2021) did not, so far as I can find, assert the '655 patent. Those suits — FISI v. Coolpad Group (2:20‑cv‑00117, E.D. Tex.), FISI v. Belkin (1:20‑cv‑00550, D. Del.), FISI v. Lenovo (United States) (1:20‑cv‑00551, D. Del.), FISI v. TCT Mobile (US) (1:20‑cv‑00552, D. Del.), and FISI v. Denso Int'l America / Toyota et al. (2:21‑cv‑00281, E.D. Tex.) — centered on the Fischer patents ('936 family: '111, '550, '766, '586) and related patents such as '233, '422, and '319. The Belkin AO‑120 filing, for example, lists 7,239,111; 8,624,550; 7,453,233; 6,936,936; and 8,330,422 — not the '655. I flag this as a negative finding based on the records I could retrieve; I cannot rule out that the '655 appeared in a complaint or amended pleading not surfaced in these searches.
• Exact filing days for cases 2:17‑cv‑00145, 2:16‑cv‑01424, and 2:16‑cv‑01425 are approximate (2027/2016 respectively); the service dates I could confirm are the Samsung service (Feb. 23, 2017) and the ZTE Amended Complaint service (May 12, 2017). If you need exact docket filing dates, they should be pulled directly from PACER for each case number.
• Interpreted literally, the patent number in the assignment/priority records cited (7,893,655 / application 12/716,535) matches the target patent; I did not substitute or auto-correct any identifier, and I excluded results for similar numbers (e.g., '173/7,701,173, '058/7,965,058, and the Fischer '550/'111/'766/'586 patents) except where they are directly relevant as family members or co-asserted patents.

If you want, I can pull the exact PACER filing dates and docket entries for each of the four district-court cases, or the final written decision text of IPR2018-00425, to firm up the record.

I'll research the PTAB proceedings on US 7,893,655. The structured block conflicts with the patent's own prosecution history (which shows four IPR numbers), so I need to verify via web search.

Good data on Huawei's IPR. Now let me research the ZTE/Samsung IPR with the Final Written Decision, plus the LG and second ZTE proceedings.

Now the critical detail — the actual outcome of the ZTE/Samsung FWD. Let me pin that down plus any appeals.

PTAB / AIA Trial Proceedings — US 7,893,655 ("Charging and power supply for mobile devices")

⚠️ Data discrepancy flagged first. The structured "PTAB proceedings on file" block for this prompt reports no AIA trial proceedings from the USPTO Open Data Portal ingest. That is wrong for this patent. The Google Patents record for US 7,893,655 (and the USPTO legal-events field on that record, which I treat as authoritative over the ODP-derived block) lists four AIA trial proceedings and an issued IPR certificate. I rely on the patent record + web sources below and flag ODP as out of date rather than defaulting to "no activity."

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Proceedings overview

Four AIA trial proceedings were filed against US 7,893,655: one reached a Final Written Decision (IPR2018-00425, certificate issued 2019-10-24), two settled after institution (IPR2018-00479, IPR2018-00683), and one was denied institution (IPR2018-01076) — none are active. Critically, I was unable to retrieve the FWD text, so I cannot tell you which claims, if any, were canceled; I will not tell you "claims 1-5 are canceled." The bottom line is uncomfortable for a defendant hoping for a clean kill: claims 1–11 were put in play three separate times by three separate OEMs in a seven-week window in 2018, the patent survived to a FWD, and the patentee paid maintenance fees through the 12th year (2022-08-22) — consistent with at least some claims surviving. You cannot assume this is a dead patent; get the FWD before you rely on any prior-art shortcut.

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IPR2018-00425 — ZTE Corporation, ZTE (USA) Inc., and Samsung Electronics (Co./America) v. Fundamental Innovation Systems International LLC

• Type: Inter Partes Review
• Filed: 2018-01-05 (petition); docketed/e-filed event 2018-02-13 per USPTO legal events
• Status: "Final Written Decision" (per Google Patents/Unified Patents structured field). Plain English: the trial ran to judgment and the resulting § 318(b) certificate issued — but the FWD's claim-level disposition is not public in the sources I could retrieve.
• Judge panel: APJs Paul J. Korniczky (opinion author), Lynne E. Pettigrew, Jo-Anne M. Kokoski
• Petition grounds: claims 1–11 challenged under 35 U.S.C. § 103 — (1) claim 1 as obvious over Veselic in view of Vyssotski; (2) claims 2–11 as obvious over Veselic, Vyssotski, and Kranzen (see the -00425 petition, Paper 1 at 12–13, as quoted in the IPR2018-01076 Patent Owner Preliminary Response). Note the primary reference "Veselic" is the inventor's own earlier disclosure — a self-art obviousness attack.
• Institution decision: Instituted 2018-07-06 (all challenged claims/grounds).
• Final Written Decision: issued 2019-07-02. Claim-level verdict: NOT VERIFIED — I could not obtain the FWD. Do not rely on a second-hand characterization of this document.
• Settlement / termination: none — this one went the distance.
• Appeal: No evidence of a Federal Circuit appeal. Strong (not conclusive) inference: the § 318(b) certificate issued 2019-10-24 (USPTO legal event recorded 2019-10-29, IPRC/K1), which is inside the 63-day notice-of-appeal window (which would have closed around 2019-09-03 had FIS appealed). A certificate cannot issue while an appeal is pending. So the FWD appears to have become final without appeal.
• Notable procedural ruling worth knowing: IPR2018-00425, Paper 34 (2019-02-06) — the Board permitted ZTE to retroactively add ZTE (TX) Inc. as a real party in interest, curing a § 312(a)(2) defect and avoiding a § 315(b) time bar, finding "no evidence of intentional concealment, bad faith, or an attempt to circumvent estoppel rules" and that the amendment served "the interest of justice." See discussion at Mondaq analysis.
• Defensive value: This is the only proceeding that produces § 315(e)(2) estoppel, and it binds ZTE and Samsung and their privies/RPIs — not Huawei, not LG, not you. If you are an unrelated defendant, the Veselic/Vyssotski/Kranzen art remains fully available to you in district court; if you are in the ZTE/Samsung corporate orbit, it is not.

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IPR2018-00479 — Huawei Device Co., Ltd. (and [Huawei Technologies Co., Ltd.](/litigations/by-plaintiff/Huawei%20Technologies%20Co.%2C%20Ltd.)) v. Fundamental Innovation Systems International LLC

• Type: Inter Partes Review
• Filed: 2018-01-12
• Status: "Settlement" (docket status: Terminated-Settled). Termination decision: 2018-09-27.
• Judge panel: APJs Pettigrew, Kokoski, and Korniczky (author of the termination decision)
• Petition grounds: claims 1–11 challenged (per PTAB docket summary).
• Institution decision: instituted 2018-08-08 (Paper 7).
• Final Written Decision: none — terminated before Patent Owner's Response was filed.
• Settlement / termination: Joint motion to terminate under 35 U.S.C. § 317(a) filed 2018-09-21 with a true copy of the written agreement (Ex. 2011); granted 2018-09-27. The Board ordered the agreement treated as business confidential and kept separate from the patent file under 37 C.F.R. § 42.74(c) — terms are confidential. The parties stated they agreed to dismiss with prejudice the co-pending E.D. Tex. action (Civil No. 2:16-cv-01424-JRG-RSP) and this IPR. Board citation: Termination Decision, IPR2018-00479 (Paper 14).
• Appeal: none (no FWD to appeal).
• Defensive value: No estoppel attaches — Huawei walked away clean. Useful for you only as leverage/context: it shows Huawei's stipulated exit (and dismissal of the E.D. Tex. case) is what killed ZTE's joinder play (see IPR2018-01076 below).

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IPR2018-00683 — LG Electronics, Inc. (and LG Electronics U.S.A., LG MobileComm U.S.A., LG Mobile Research U.S.A., LG Alabama) v. Fundamental Innovation Systems International LLC

• Type: Inter Partes Review
• Filed: 2018-02-22
• Status: "Settlement" (docket status: Terminated-Settled). Termination decision: 2018-10-31.
• Judge panel: APJs Korniczky, Pettigrew, Kokoski
• Petition grounds: claims 3, 5, 6, 8, 10, and 11 challenged — a narrower set than the ZTE/Huawei petitions (LG did not challenge claims 1, 2, 4, 7, 9).
• Institution decision: instituted 2018-09-27.
• Final Written Decision: none — settled approximately one month after institution.
• Settlement / termination: terminated on joint request; terms confidential.
• Appeal: none.
• Defensive value: No estoppel for LG. The carve-out matters analytically: LG appears to have deliberately avoided independent claim 1, which is the claim FIS leaned on most heavily — a possible tell about which claim LG's engineers/experts thought was weakest or which claim FIS was asserting against LG.

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IPR2018-01076 — ZTE Corporation and ZTE (USA) Inc. v. Fundamental Innovation Systems International LLC

• Type: Inter Partes Review (follow-on petition, filed with a motion for joinder under 35 U.S.C. § 315(c) / 37 C.F.R. § 42.122(b))
• Filed: 2018-05-14
• Status: "Not Instituted - Procedural" (PTAB docket status: Institution Denied). Decision: 2018-12-03.
• Judge panel: APJs Korniczky, Pettigrew, Kokoski
• Petition grounds: claims 1–11 under § 103 — but a reordered combination: Kranzen, Veselic, and Vyssotski — i.e., materially the same art as IPR2018-00425, just re-sequenced and with Kranzen moved to the primary-reference slot.
• Institution decision: DENIED 2018-12-03, and the motion for joinder was denied (docket entry: "Order - Denying Motion for Joinder - 35 USC 315(c); 37 CFR 42.122(b)"). The Board exercised § 314(a) / General Plastic discretion against this serial follow-on petition, and FIS's opposition argued the petition was (a) barred because ZTE (TX) was an unnamed RPI and the petition was filed more than a year after Samsung (co-petitioner/RPI) was served, and (b) an impermissible second bite at the same claims and art. The Board also could not join because the target proceeding (Huawei's IPR2018-00479) had already been terminated on settlement — a terminated proceeding cannot be joined.
• Final Written Decision: none.
• Settlement / termination: N/A (denied at institution).
• Appeal: none; § 314(a) institution denials are non-appealable.
• Defensive value: This is a cautionary tale, not a weapon. It shows the Board will refuse to let a petitioner hold back art for a second petition. If your invalidity case depends on Veselic/Vyssotski/Kranzen, understand that ZTE's failure here does not bar you, but it does mean you should put everything in one petition the first time — § 315(e)(2) estoppel will bite on grounds you "reasonably could have raised."

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Strategic summary

Claim status — CANCELED vs. SUSTAINED vs. UNTESTED. Disclaimer up front: I could not retrieve the IPR2018-00425 FWD or the § 318(b) certificate text, and I will not guess at claim numbers. What is verified: the patent has 11 claims — independent claim 1 (method) with dependent claims 2–7, and independent claim 8 (device) with dependent claims 9–11. Claims 1–11 were all challenged in IPR2018-00425 and in IPR2018-00479; LG's IPR2018-00683 challenged only claims 3, 5, 6, 8, 10, 11. Nothing is "untested" — every claim was challenged at least once. The one FWD produced a certificate (issued 2019-10-24); whether it canceled claims or confirmed them is the single open question you must close. Circumstantial evidence favors survival of at least some claims: FIS paid the 12th-year maintenance fee on 2022-08-22, nearly three years after the certificate — an owner does not pay ~$8k+ to maintain a patent whose every claim was canceled in 2019. (Not conclusive — annuity docketing can run on autopilot — but it is the best structural signal available.)

Estoppel landscape. § 315(e)(2) estoppel attaches only to petitioners who obtained a FWD — here, ZTE and Samsung and their privies/RPIs (IPR2018-00425). Huawei and LG have no estoppel (both settled pre-FWD, IPR2018-00479 and IPR2018-00683). If you are a defendant being asserted today, then: (i) if you are unrelated to ZTE/Samsung, the Veselic, Vyssotski, and Kranzen references — plus Kranzen-primary permutations — remain available in district court, subject to the ordinary rules; (ii) if you are in the ZTE/Samsung orbit (including through an RPI/privy relationship), assume the entire Veselic/Vyssotski/Kranzen ground is estopped, and mind the CAFC's expansive RPI jurisprudence (Applications in Internet Time, LLC v. RPX Corp., 897 F.3d 1336 (Fed. Cir. 2018)) — the Board in this very case let ZTE add a missing RPI retroactively. The practical edge: because a FWD exists on claims 1–11, a § 315(e)(2) estoppel argument by the patentee is live against ZTE/Samsung and would be a strong summary-judgment tool — note that FIS has already successfully used precisely this play in its parallel campaign against ZTE on the '550 patent (N.D. Tex. No. 3:17-cv-1827, briefing at Dkt. 200).

Pattern signals. This is a coordinated NPE monetization campaign, not a one-off. Three separate smartphone OEM groups — ZTE+Samsung together (2018-01-05), Huawei (2018-01-12), LG (2018-02-22) — filed within seven weeks of each other, all on claims 1–11 with overlapping art, all exactly one year (or less) after FIS served complaints in E.D. Tex. (2:16-cv-01424, Huawei; 2:16-cv-01425, LG; 2:17-cv-00145, Samsung) — classic § 315(b) one-year-bar timing. No defensive aggregator (e.g., Unified Patents) appears as petitioner; Unified appears only as the litigation-data host for the structured links. Patent owner is Fundamental Innovation Systems International LLC, an NPE that acquired the portfolio from BlackBerry Limited on 2015-11-19 (recorded 2015-12-17 and again 2016-12-01). FIS did not appeal the one adverse/instituting FWD (based on the certificate timing), so there is no Federal Circuit opinion on the '655 — the In re IPR Licensing / ZTE appeal in the search results is a different patent and a different dispute and should not be attributed here.

One more thing that changes the whole posture: the patent's 20-year term ran out on 2025-12-13 ("Anticipated expiration"; status "Expired - Lifetime"). There is no prospective injunction value left in the '655 — any demand you receive is a past-damages play on the § 286 six-year lookback (i.e., roughly 2019–2025 sales at most). That materially caps the exposure and strengthens your settlement leverage.

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Recommended next steps

1. Pull the FWD and the certificate — this is priority one. Download IPR2018-00425, Final Written Decision (2019-07-02) and the § 318(b) Inter Partes Review Certificate (issued 2019-10-24) from PTAB E2E (or the PTAB API at https://developer.uspto.gov/ptab-api). The certificate text states, claim by claim, exactly what was "cancel[led] … finally determined to be unpatentable" versus "confirm[ed] … determined to be patentable." Until you read it, do not build an infringement or invalidity theory on any assumption about claims 1–11. Structured metadata links: Unified Patents IPR2018-00425.

2. If the certificate canceled claims 1–11: the patent is a shell — any demand citing those claims is baseless, and quote the certificate's cancelation language directly in your response letter. If it confirmed some or all: treat the claims as hardened by a survived IPR and shift to different art than Veselic/Vyssotski/Kranzen (which ZTE/Samsung already threw at it), or to § 112 / § 101 theories, or to the sibling patents — see next step.

3. Map the family before you negotiate. The '655 is a continuation of US 7,701,173 (US 11/299,701, filed 2005-12-13, "Active" until 2028-07-03) and has a continuation child US 7,965,058 (US 13/004,175). FIS's campaign also runs on the '936 family — US 7,239,111, US 7,834,586, US 8,232,766, US 8,624,550 — which it litigated hard in N.D. Tex. Fundamental Innovation Sys. Int'l v. ZTE, No. 3:17-cv-1827 (see the court's summary-judgment order at Justia). A demand letter asserting only the '655 may be a test balloon; expect the '173/'058 or '936-family patents to follow. Check whether the same art you use against the '655 was already exhausted against the siblings.

4. No active proceedings to calendar. IPR2018-00425 is final (certificate issued 2019-10-24), IPR2018-00479 and IPR2018-00683 terminated on settlement (2018-09-27 and 2018-10-31), and IPR2018-01076 was denied institution (2018-12-03). There are no pending PTAB milestones — no institution deadline, no oral hearing, no statutory 1-year FWD due date — against this patent. Any new IPR you file would be a fresh proceeding: note the one-year § 315(b) bar runs from service of your complaint, and the patent expired 2025-12-13, so weigh whether post-expiration IPR spend is even justified.

5. If you are a ZTE/Samsung affiliate or privy: assume full § 315(e)(2) estoppel on the Veselic/Vyssotski/Kranzen ground for claims 1–11 and do not re-run it in litigation — the patentee has already demonstrated (in the '550 case) that it will move for summary judgment on exactly this theory.

I'll verify the assignment chain and litigation context with targeted searches before writing up.

Now let me try to pin down the recorded correspondents and the FISI ownership/backing details.

Let me attempt to retrieve the recording correspondents directly and confirm any additional recorded assignments.

Inventors

Unusual-pattern check:

• The patent has exactly one inventor, which is atypical for a mixed-signal power/charging architecture and means there is no multi-inventor departure pattern to test. I found no evidence that Veselic left RIM within 12 months of the 2005-12-13 filing; on the contrary, his name recurs on RIM filings through the mid-2000s. I am not asserting a departure — the data available to me does not support one.
• The genuinely odd item is timing of perfection, not of inventorship: the inventor→RIM assignment was executed 2005-12-12 (one day before the 2005-12-13 filing date) but was not recorded until 2010-03-03 — the same day the continuation application US 12/716,535 (this patent) was filed. That 4.3-year execution-to-recording gap is consistent with the assignment being re-recorded to perfect title for the continuation rather than with any portfolio event. Recorded at Reel 024022/0904.

Original assignee

Research In Motion Limited (RIM), Waterloo, Ontario, Canada — original assignee on the face of the issued patent (US 7,893,655 B2, granted 2011-02-22).

• Primary line of business: design/manufacture of wireless handheld communication devices (BlackBerry). RIM was a vertically integrated operating company that made the hardware, OS, and charging ecosystem the claims describe.
• Product embodying the claims: the specification's architecture (switch-mode battery charging + system power supply + battery isolation at a V_SYS node, USB-compliant startup under 100 ms) is the shipping BlackBerry charging/USB power architecture of that era. RIM shipped devices charged over USB from cradle/dock and USB port, and the patent's own framing is explicitly USB-compliance in a handheld device. I have not independently inspected a teardown to confirm claim-by-claim read on a specific RIM SKU, so treat "shipped practice" as strongly supported but not forensically verified here.
• Current status (as of 2026-09-30): operating, but no longer in the handset business. RIM changed its name to BlackBerry Limited (effective 2013-07-09; recorded 2015-08-17 at Reel 036356/0472). BlackBerry subsequently exited device manufacturing. It was not insolvent — there is no Chapter 7/11 proceeding in the chain.

Important status fact for the patent itself: the Google Patents legal-status entry shows anticipated expiration 2025-12-13 and status "Expired – Lifetime." The patent is therefore lapsed as of today's date, and the FISI enforcement campaign on the '655 patent is historical.

Assignment timeline

Recorded assignments retrieved (source: Google Patents legal-events feed for US 7,893,655 B2, which mirrors the USPTO Assignment Center records; four recorded assignment events total).

Data caveat on correspondents: Google Patents' legal-events feed exposes the reel/frame, conveyance, assignor, assignee and dates, but not the "correspondent of record" field, and I was unable to load the Assignment Center record pages themselves in this environment. I am therefore not naming any correspondent rather than guessing. Signal 3 below is scored accordingly.

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• 2005-12-12 (executed) / recorded 2010-03-03 — Reel 024022/0904

  • Conveyance: Assignment
  • Assignor: Dusan Veselic
  • Assignee: Research In Motion Limited
  • Correspondent: Not retrievable from available sources (see caveat above).
  • Context: Original inventor-to-employer assignment; executed the day before the 2005-12-13 filing and recorded ~4.3 years later, on the same date the continuation US 12/716,535 was filed.

• 2013-07-09 (effective) / recorded 2015-08-17 — Reel 036356/0472

  • Conveyance: Change of Name (no transfer of title)
  • Assignor: Research In Motion Limited
  • Assignee: BlackBerry Limited
  • Correspondent: Not retrievable.
  • Context: Internal corporate reorg / change of name only. Note the ~2-year lag between the effective date (2013) and recording (2015) — the recording was cleaned up in the same window as the portfolio sale that followed four months later.

• 2015-11-19 (executed/effective) / recorded 2015-12-17 — Reel 037324/0978

  • Conveyance: Assignment
  • Assignor: BlackBerry Limited
  • Assignee: Fundamental Innovation Systems International LLC
  • Correspondent: Not retrievable.
  • Context: Transfer to asserter — sale of the former BlackBerry USB-charging portfolio (reported as 55+ US assets plus foreign counterparts; other accounts put the wider transaction at 158–200 assets) to a Centerbridge Partners–backed Delaware LLC.

• 2015-11-18 (executed/effective) / recorded 2016-12-01 — Reel 040792/0483

  • Conveyance: Assignment
  • Assignor: BlackBerry Limited
  • Assignee: Fundamental Innovation Systems International LLC
  • Correspondent: Not retrievable.
  • Context: Second recordation of the same November 2015 transaction (effective date one day earlier than the Reel 037324/0978 link). Two same-assignor→same-assignee assignments with near-identical effective dates, recorded a year apart, is consistent with the deal being recorded in tranches (US vs. foreign assets) or a confirmatory recording rather than two distinct purchases.

No records found for: security agreements, licenses, releases, merger conveyances, or any post-2016 transfer. FISI remains the record owner, and there is no assignment terminating the chain at a defensive aggregator.

Timeline diagram

timeline
    title Ownership of US 7893655
    2005 : Inventor assigns rights to Research In Motion
    2010 : Continuation filed and original assignment recorded
    2013 : Research In Motion renamed BlackBerry Limited
    2015 : BlackBerry sells portfolio to FISI
         : Recorded at Reel 037324
    2016 : Second FISI recordation at Reel 040792
         : FISI sues LG and Huawei over this patent
    2017 : FISI sues ZTE and Samsung over this patent
    2018 : IPRs filed by Samsung ZTE Huawei and LG
    2019 : IPR certificate issued October 24
    2025 : Patent reaches anticipated expiry

NPE / troll-pattern signals

1. Shell-entity transfer — PRESENT.
Reel 037324/0978 (effective 2015-11-19, recorded 2015-12-17) moves US 7,893,655 from BlackBerry Limited, an operating company, to Fundamental Innovation Systems International LLC, a Delaware LLC formed in 2015. RPX describes FISI as "an NPE with active campaigns in the US and Europe" whose corporate parent is Fundamental Innovation Systems International Holdings LLC (Delaware-entity/single-purpose structure; the parent is separately named in Apple's 2019 DJ action). The LLC has no products in commerce; its function is licensing and assertion. Backing is by Centerbridge Partners, a private-equity firm, per filings in the Ocean Tomo / Michael Friedman litigation.

2. Known asserter in the chain — PRESENT.
FISI is not on the classic enumerated list (Acacia, Marathon, IV, Wi-LAN, Round Rock, etc.), but it is a documented high-frequency plaintiff tracked by RPX: "roughly 20 suits since late 2016," naming Apple, Aukey, BBK/OnePlus, BLU, Hon Hai/Belkin, Huawei, Jasco, Lenovo, LG, Samsung, TCL, Coolpad, ZTE, Anker/Fantasia and Cyber Power. US 7,893,655 specifically appears in 2:16-cv-01424 (Huawei, filed 2016-12-16), 2:16-cv-01425 (LG, filed 2016-12-16), 2:17-cv-00124 (ZTE, filed 2017-02-13) and 2:17-cv-00145 (Samsung, filed 2017-02-21) — all in E.D. Tex. before Judge Gilstrap.

3. Repeat correspondent across the chain — UNCLEAR (data not retrievable).
I was unable to retrieve the correspondent-of-record field for any of the four recordations (Reels 024022/0904, 036356/0472, 037324/0978, 040792/0483). I will not name an attorney without the record. What to check if you pull the Assignment Center pages: whether one filing attorney recurs across Reels 037324/0978 and 040792/0483, and whether that same name appears on the recordations for the sibling family members US 7,701,173 and US 7,965,058 — a single recurring filer across the FISI tranches is the highest-value remaining check.

4. Cascading transfers — PARTIALLY PRESENT / weak.
The chain is short (three substantive links), so there is no multi-LLC cascade. But there are two recordations from BlackBerry to the same FISI entity effective 2015-11-18 and 2015-11-19, recorded 2015-12-17 and 2016-12-01 respectively — i.e., a year apart for effectively the same transaction. Combined with the RIM→BlackBerry name change recorded only months before the sale (Reel 036356/0472, recorded 2015-08-17), the record shows title being cleaned up and then moved within a 16-month window. I score this weak, not strong: the near-identical effective dates point to tranching/confirmatory recording, not to chained shell intermediaries.

5. Pre-litigation transfer — NOT PRESENT (fails the 6-month test).
The transfer to FISI was effective 2015-11-18/19; the first suit naming the '655 patent was filed 2016-12-16 (Huawei and LG) — approximately 13 months, outside the 6-month window. Precision matters here: the campaign was plainly enabled by the transfer, but the assignment is not "within 6 months before the first suit." (Note: FISI was sending licensing demands to Apple from late 2015, i.e., immediately on acquisition, which is demand-letter timing, not litigation timing.)

6. Bankruptcy fire-sale — NOT PRESENT.
No Chapter 7/11 for Research In Motion or BlackBerry in the chain. RIM/BlackBerry's device business declined and was exited, but the 2015 transaction was a solvent, negotiated portfolio monetization, not a bankruptcy sale. No bankruptcy docket appears in the legal events.

7. Privateering — UNCLEAR.
The pattern superficially fits (operating company → NPE → suits against the operating company's competitors), but classic privateering requires evidence the operating company retains an interest or directs the assertion. Here the record shows an outright sale to a Centerbridge-backed vehicle that was separately engaged with monetization intermediaries (initially TnT IP LLC, then former IPVALUE executives Kapu Kumar, Paul Seaman and Paul Riley, per IAM/RPX), with no evidence of a BlackBerry revenue share or control right. I therefore do not score this as present.

8. Defensive aggregator — NOT PRESENT.
The chain terminates at FISI (Reels 037324/0978 and 040792/0483). There is no RPX, AST, LOT, Unified Patents, or OIN link — this patent was asserted, not neutralized.

Post-transfer litigation/validity note (context, not a signal): four IPRs were filed against the '655 patent in 2018 — IPR2018-00425 (ZTE/Samsung, instituted, Final Written Decision; an inter partes review certificate issued 2019-10-24), IPR2018-00479 (Huawei, settled), IPR2018-00683 (LG, settled) and IPR2018-01076 (ZTE, institution denied as procedural/joinder).

Verdict

NPE — high confidence.

Two strong signals are established on the record, not on naming: (a) a licensing-only shell transfer at Reel 037324/0978 (effective 2015-11-19), moving the patent out of operating-company BlackBerry into Delaware-formed Fundamental Innovation Systems International LLC, a no-product entity with a Delaware holdings parent and Centerbridge Partners backing; and (b) a known high-frequency asserter — FISI is tracked by RPX as an NPE with ~20 suits since 2016, and this patent was asserted in E.D. Tex. against Huawei (2:16-cv-01424), LG (2:16-cv-01425), ZTE (2:17-cv-00124) and Samsung (2:17-cv-00145). The chain does not satisfy the 6-month pre-litigation-transfer test (transfer Nov 2015, first '655 suit Dec 2016) and does not involve bankruptcy; the correspondent-recurrence check remains unresolved for lack of the correspondent field. Note that the patent expired 2025-12-13 and is now "Expired – Lifetime," so this is a historical rather than live campaign.

Verify at: https://assignmentcenter.uspto.gov/ (search patent number 7893655) — the reel/frame entries to pull are 024022/0904, 036356/0472, 037324/0978 and 040792/0483; the correspondent field on the latter two is the key remaining check. Mirror index: https://assignment.uspto.gov/patent/index.html. Legal-events cross-reference: https://patents.google.com/patent/[US7893655B2](/patent/US7893655B2)/en.

I'll research this patent and its cited prior art. Let me start with targeted searches.

Let me gather more detail on the key prior-art references and the IPR proceedings.

Prior-Art Analysis — US Patent No. 7,893,655 (US7893655)

Strict-ID compliance note: I interpreted the identifier 7893655 literally as granted US 7,893,655 B2. I did not substitute any similar number. Everything below is drawn from the patent's own authoritative record (Google Patents front page + full text, cited at https://patents.google.com/patent/US7893655/en), which lists the references the USPTO considered. I was unable to complete a separate live pull of the USPTO PatentCenter/PTAB documents before my tool budget expired — that limitation is noted where relevant.

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1. The patent at a glance

Claim architecture (what any §102 reference must meet):

• Claim 1 (method): generate output power → receive a reference voltage from the electronic system → determine, based on that reference voltage, a minimum voltage at a node directly connected to the system power input → sense the node voltage is below the minimum → restrict current from the output power to the battery.
• Claim 2: dependent — the generating step derives output power from an external source at higher current/lower voltage (i.e., switch‑mode).
• Claim 3 (USB‑compliant circuit): switch‑mode charging circuitry (IC + inductor, output current > external current) + battery‑isolation circuitry that receives a reference voltage from the electronic system, determines a minimum node voltage, senses a below‑minimum condition, and controls a switch to restrict battery current.
• Claims 4–7: dependents on 3 (SMPS-on-battery path; output-node feedback to the IC; DC‑DC converter IC; converted power through output node).
• Claim 8 (device): housing + battery + electronic system + the claim‑3 style circuit.
• Claims 9–11: dependents on 8 (battery‑powered conversion; semiconductor switch; switch‑off when charging disabled).

The single most limiting element across the independent claims is "receive a reference voltage from said electronic system" (claims 1, 3, 8). A reference that merely regulates the bus/node to a fixed, internally generated setpoint does not anticipate these claims.

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2. Patent citations of record (22) — citation, dates, description, §102 potential

Caveat applied throughout: being "cited" means the examiner/applicant considered it; it does not establish anticipation. True §102 anticipation requires every claimed element in a single reference, arranged as in the claim. Below I flag the closest art and the missing element.

1987–1995

1. US 5,179,335 A — Norvik Inc., "Battery charger" (filed 1987‑10‑09; published 1993‑01‑12)
Battery charger that monitors charging and terminates/controls charge. §102: Charger-side control only; no electronic‑system reference voltage, no node-voltage current‑steering. Anticipates no claim; background art.

2. EP 0 623 985 A1 — SGS‑Thomson Microelectronics Pte Ltd, "Power Sharing detector" (filed 1993‑05‑05; published 1994‑11‑09)
Directs to sharing available input power between a system load and a battery charger. §102: Conceptually the closest to the "current split" idea of claims 1/3, but it shares power by a detector on the source side, not by sensing an output node against a minimum derived from a system‑supplied reference voltage. Potentially relevant to the preamble/general concept of claims 1 and 3, but does not anticipate them as issued.

3. US 5,432,427 A — Chiang, Chih‑Cheng, "Battery charging control system" (filed 1993‑11‑23; published 1995‑07‑11)
Battery charging control that coordinates charging with load conditions. §102: No system-supplied reference voltage; no switch-mode IC/inductor current-boost limitation. Background art.

4. EP 0 752 748 A1 — STMicroelectronics S.r.l., "Multiple function battery charger, self-configuring as supply voltage regulator for battery powered apparatuses" (filed 1995‑06‑07; published 1997‑01‑08)
A charger that doubles as a supply-voltage regulator for the host. §102: Relevant to the "charge and supply from one converter" concept (claims 3, 4, 7, 9), but does not disclose a system‑provided reference voltage defining the node minimum. Background/§103 art.

5. US 5,694,022 A — Selfcharge, Inc., "Variable pulse recharging battery pack" (filed 1995‑12‑18; published 1997‑12‑02)
Pulsed charging of a battery pack. §102: Battery-side charging algorithm; no relevance to the node‑voltage/current‑steering element. Background art.

1995–2001

6. US 5,939,862 A — Dell USA L.P., "Adaptive power battery charging apparatus" (priority 1995‑10‑20; filed 1997‑11‑19; published 1999‑08‑17)
Adaptive charger that monitors adapter power and gives the battery only what the portable device does not use — battery power decreases as system demand rises and increases as system demand falls (see the patent's t1–t9 narrative). §102: This is substantively close to the "restrict current to the battery so the system gets its power" concept of claims 1/3/8. However, it senses adapter power/current and battery voltage, not a reference voltage received from the electronic system to set the node minimum. Potential §103 lead against the power‑allocation concept; does not anticipate the independent claims.

7. US 6,031,359 A — Chartec Laboratories A/S, "Digitally controlled switch-mode power supply for charging rechargeable batteries" (filed 1996‑10‑10; published 2000‑02‑29)
Digitally controlled switch-mode charging supply. §102: Touches the switch-mode charging element (claim 2/3) but lacks the isolation/current-steering circuitry. Background art.

8. US 6,222,347 B1 — Apple Computer, Inc., "System for charging portable computer's battery using both the dynamically determined power available based on power consumed by sub-system devices and power limits from the battery" (filed 1998‑04‑30; published 2001‑04‑24)
Charges the battery using power dynamically left over after sub-system consumption, bounded by battery limits. §102: Very close conceptually to allocating leftover power to the battery (claims 1/3/8), but power is computed from system consumption and battery limits, not from a system‑supplied reference voltage. §103 lead; not anticipatory.

9. US 6,100,664 A — Motorola Inc., "Sub-miniature high efficiency battery charger exploiting leakage inductance of wall transformer power supply, and method therefor" (filed 1999‑03‑31; published 2000‑08‑08)
Compact high-efficiency charger. §102: Charger implementation detail; nothing on system-referenced node regulation. Background art.

10. US 6,118,254 A — Compaq Computer Corporation, "Battery charge control architecture for constant voltage maximum power operation" (filed 1999‑07‑30; published 2000‑09‑12)
The most structurally on‑point cited reference: a constant-voltage source drives a power bus feeding both a dynamically varying load and a battery-charging regulator; the regulator limits battery charge current so the bus is not pulled below a second voltage setpoint (e.g., 18 V), holding the source near peak power — done without microprocessors/arbitration. §102: It discloses the core "sense bus/node voltage → reduce battery current to protect the system rail" mechanism of claims 1 and 3, and a buck (switch-mode) converter (≈claims 2/4/6/7). The setpoint, however, is established internally (resistor/sense network), not by a reference voltage received from the electronic system. So it is a strong §103 reference against claims 1/3/8 but does not, on its face, anticipate them as issued. Its dependent-claim subject matter (switch-mode buck regulation, current-limit feedback) is potentially anticipatory of claims 2, 4, 6, 7 standing alone.

11. US 6,300,744 B1 — Siliconix Incorporated, "High-efficiency battery charger" (filed 2000‑02‑10; published 2001‑10‑09)
High-efficiency (switch-mode) charger topology. §102: Relevant to switch-mode charging (claims 2/3), not to the node‑voltage steering. Background art.

12. US 6,188,199 B1 — Eldec Corporation, "Battery charge optimizing system" (filed 2000‑03‑31; published 2001‑02‑13)
Charge-optimizing system. §102: No disclosure of system‑referenced minimum node voltage. Background art.

2000–2003

13. US 6,741,066 B1 — O2Micro International Limited, "Power management for battery powered appliances" (priority 2000‑09‑21; published 2004‑05‑25)
Feedback-enabled adapter/charge-controller topology: error amplifiers monitor battery voltage/current and input‑power availability and feed the adapter to modulate duty cycle; the system can throttle charging based on system power requirements. §102: Strong §103 reference on the "report a system/battery condition and reduce charge current accordingly" theme and on switch-mode control (claims 2–7). It does not disclose a reference voltage received from the electronic system to set a node minimum, so it does not anticipate claims 1/3/8. Note the same O2Micro family (EP 2 602 922 A3, "Power management system for Universal Serial Bus," error amplifier comparing output voltage to a load-operating reference) reflects this line of art.

14. JP 2003‑032910 A — Mitsubishi Electric Corp., "Terminal device" (filed 2001‑07‑13; published 2003‑01‑31)
Terminal power/charging arrangement. §102: Jurisdictional/background art; no teaching of the system-referenced node minimum. Background art.

2003–2004 (the applicant's own RIM/Veselic family — highly relevant)

15. US 2004/0164708 A1 — Dusan Veselic (RIM), "Circuit and method of operation for an electrical power supply" (filed 2003‑02‑21; published 2004‑08‑26)
16. WO 2004/075371 A1 — Research In Motion Limited, "Circuit and method of operation for an electrical power supply" (filed 2003‑02‑21; published 2004‑09‑02)
17. US 2004/0164707 A1 — Dusan Veselic (RIM), "Circuit and method of operation for an adaptive charge rate power supply" and 18. US 2005/0046391 A1 — Research In Motion (same family), "Circuit and method of operation for an adaptive charge rate power supply" (filed 2003‑02‑21; published 2004‑08‑26 / 2005‑03‑03)
These are the same inventor's earlier RIM work on adaptive charge-rate power supplies for USB/bus-powered devices. §102: Most relevant for §102/§103 against claims 1, 3, 8, because they address charging from a limited bus while supplying the device. The examiner's citation of them here (and their recurrence on the family) signals they were the primary starting point for the current claims. Whether they disclose the exact "reference voltage received from the electronic system" element is the crux — if they do, they would be anticipatory; if not, they are the principal §103 base. (I could not verify the claim-chart level of detail within my search budget; this is the item I would verify first against the IPR record.)

19. US 7,208,892 B2 — The Hoover Company, "Power management system for a floor care appliance" (filed 2003‑05‑23; published 2007‑04‑24)
Appliance power management. §102: Different field; cited for generic power-management background. Background art.

20. US 2004/0239294 A1 — Dusan Veselic, "Method and apparatus for handling a charging state in a mobile electronic device" (filed 2003‑05‑27; published 2004‑12‑02)
Charging‑state handling for mobile devices. §102: Same inventor; relevant to charging‑state control (claim 11's "charging disabled" concept) but not to the node‑voltage/current‑steering core. Background/§103 art.

21. US 2004/0251878 A1 — Dusan Veselic, "Universal Serial bus charger for a mobile device" (filed 2003‑06‑11; published 2004‑12‑02)
USB charging architecture for a mobile device. §102: Directly relevant to the "USB‑compliant charging and power supply circuit" preamble of claim 3 and to supply-from-bus concepts. Combined with the adaptive-charge-rate family (refs 15–18), it is the strongest single body of art against claims 3/8 preambles, though again the system‑provided reference‑voltage element is the likely gap.

22. US 2006/0022640 A1 — Peter Frith, "Power supply circuit for portable battery powered device" (filed 2004‑07‑26; published 2006‑02‑02)
Portable power‑supply circuit with switch‑mode conversion and battery/system power paths. §102: Relevant to the switch-mode IC‑plus‑inductor power‑steering structure of claims 3–9 (potentially anticipatory of dependents 4, 6, 7, 9, 10), but no disclosure of the system‑referenced node minimum. §103 art on the independent claims.

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3. Non‑patent citations of record (7) — these are also prior art

¹ Dates as stated on the face of US 7,893,655.

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4. Bottom line — which citations are "most relevant," and §102 exposure by claim

Most relevant cited art (ranked):

1. US 2004/0164708 A1 + WO 2004/075371 A1 + US 2004/0164707 A1 + US 2005/0046391 A1 (RIM/Veselic adaptive charge‑rate power supply) — the same inventor's earlier work; the primary candidate for §102/§103 against claims 1, 3, 8.
2. US 6,118,254 A (Compaq) — closest mechanism to claims 1/3/8 ("don't let the bus drop below a setpoint; throttle battery current"), but uses an internally fixed setpoint.
3. US 6,741,066 B1 (O2Micro) and US 5,939,862 A (Dell) — adaptive allocation of leftover source power to the battery based on system demand.
4. US 2004/0251878 A1 (Veselic, USB charger) and US 2006/0022640 A1 (Frith) — USB/portable power‑supply architecture for the claim‑3/8 preambles and dependents.
5. EP 0 623 985 A1 (Power Sharing detector) — the general "share source power between load and battery" concept.

§102 exposure summary:

Overall assessment: No single cited reference appears to anticipate independent claims 1, 3, and 8 as issued, because each is missing (or at least not clearly showing) the claim's requirement to receive a reference voltage from the electronic system and to determine the node minimum based on that reference voltage — the limitation that distinguishes these continuations from the parent US 7,701,173. The cited art is, in contrast, powerful §103 material, especially the applicant's own prior RIM/Veselic adaptive‑charge‑rate and USB‑charger applications, read with Compaq's US 6,118,254 and either Dell's US 5,939,862 or O2Micro's US 6,741,066. Several dependents (notably 2, 4, 5, 6, 7, 9, 10, 11) map closely onto single references and carry genuine §102 risk.

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5. Explicit confidence limits (per operating rules)

• The citation list, dates, titles, assignees, and abstracts above are taken from the patent's own record (Google Patents rendering of US 7,893,655 B2, fetched 2026‑09‑30) and are reliable.
• My §102 "potential anticipation" judgments are analytical, based on the titles/abstracts/key passages surfaced in search; I did not exhaustively element‑chart every reference against every claim.
• I could not retrieve the PTAB Final Written Decision in IPR2018‑00425 or the resulting IPR certificate (K1, 2019‑10‑24) in this session (tool limit reached). Those documents would name the actual, adjudicated prior‑art grounds and identify which claims (if any) were cancelled or amended, and they should be consulted to finalize any invalidity position. I am not asserting anything about the outcome beyond the existence of that certificate.
• Two of the searches returned unrelated documents (a Chinese-language filing and a foreign search report); those were discarded and are not cited as prior art for 7,893,655.

I'll research the prior art grounds actually litigated against this patent before building the obviousness analysis.

Let me identify the specific prior-art references used in the IPRs and check the outcome.

Let me confirm the IPR outcome and check for any Federal Circuit appeal, since that determines the current claim scope.

Obviousness Analysis — US 7,893,655 B2 under 35 U.S.C. § 103

Note on sources and method. Unless stated otherwise, the "prior art" below is taken from the Citations (21), Patent Citations (22), and Non-Patent Citations (7) tables on the Google Patents page for US 7,893,655 (https://patents.google.com/patent/US7893655/en), cross-checked against the references Petitioners actually asserted at the PTAB. Where a reference's date disqualifies it as § 102 art, I say so explicitly rather than silently using it.

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1. Legal framework and assumptions

Level of ordinary skill in the art (POSA). A person with a bachelor's degree in electrical engineering (or equivalent) and roughly 2–5 years' experience designing power supplies and battery chargers for portable/battery-powered electronic devices, including familiarity with the USB 2.0 specification and its 100 mA / 500 mA current limits. This profile matches the expert Petitioners used in the parallel IPR against the parent '173 patent (James T. Geier, Ex. 1001 in IPR2018-00426: https://www.docketalarm.com/cases/PTAB/IPR2018-00426/Inter_Partes_Review_of_U.S._Pat._7701173/docs/01-05-2018-Petitioner/Exhibit-1001-Declaration_of_James_T_Geier.pdf).

Key claim constructions (consistent with how the parties and Board treated the terms):

• "node directly connected to said power input" → the V_SYS node (the '655 spec calls this the output node of circuitry 200 and states at 8:59–60 that it is directly connected to the system power input).
• "reference voltage" → an analog voltage level supplied to the supply circuitry (V_REF in Veselic '708; the voltage source 274 of the '655's own FIG. 3).
• "switch" → the p-channel FET 252 of the '655 (a semiconductor switch), claimed generically in claims 3 and 8 and narrowed in claim 10.

Correction to a prior-section inference. The previously generated summary speculated that the 11 displayed claims are post-IPR amended claims because they diverge from the "Description of Example Embodiments" restatement. The record suggests that inference is wrong. The parallel claim language ("an integrated circuit arranged to cooperate with said inductor to provide current … of greater magnitude than current … from said external power source") appears in the parent '173 patent as issued, as is apparent from the Patent Owner's Preliminary Response in IPR2018-00426 (https://www.docketalarm.com/cases/PTAB/IPR2018-00426/Inter_Partes_Review_of_U.S._Pat._7701173/docs/04-11-2018-Patent_Owner/Preliminary_Response-7-Patent_Owners_Preliminary_Response.pdf). Likewise, the "receiving a reference voltage from said electronic system" limitation matches verbatim the limitation Petitioners charted as element 1[c]/1[b] in the IPR2018-00425 petition. The displayed claims therefore appear to be the as-granted / as-prosecuted claims that were actually challenged, and the divergence from the description section is best explained by prosecution amendment of the claims, not by the 2019 IPR certificate. I flag that I could not retrieve the Final Written Decision or the certificate's disposition to confirm which claims (if any) were cancelled.

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2. Which references on this page actually qualify as prior art

Practical consequence: the two most "modern-sounding" NPL items on the face of the patent (the Maxim app note and the Summit press release) are unusable as prior art. Any obviousness case must be built on the 2003–2004 TI datasheets, the Veselic family, Vyssotski, Kranzen, and the § 102(b) charger/power-sharing art — which is exactly what happened at the PTAB.

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3. What the litigation record shows the art was used for

Two PTAB proceedings on this family (both on the Google Patents page under "Family has litigation") map the art directly:

• IPR2018-00425 (filed Jan. 5, 2018; instituted July 6, 2018; FWD July 2, 2019; panel Korniczky, Pettigrew, Kokoski). Grounds: (1) claim 1 obvious over Veselic + Vyssotski; (2) claims 2–11 obvious over Veselic + Vyssotski + Kranzen. (Grounds stated in the Board's General Plastic decision reproduced at https://ptacts.uspto.gov/ptacts/public-informations/petitions/[1512476](/patent/1512476)/... and confirmed by the Patexia docket summary, https://services.patexia.com/lawsuits/Samsung-Electronics-America-Inc-v-Fundamental-Innovation-Systems-International-LLC-id-[110808](/patent/110808).)
• IPR2018-01076 (ZTE's second petition, filed May 14, 2018; institution denied on General Plastic grounds). Grounds there: Kranzen + Veselic + Vyssotski, and alternatively Shum + White '220 + Vyssotski + White '555.
• IPR2018-00426 — same combination asserted against parent claim 1–12 of US 7,701,173.

The hearing transcript in the '655 IPR frames Petitioners' theory in exactly the KSR idiom (three "well known" concepts: switch/current-restriction between charger and load; dynamic adjustment of that restriction; switch-mode efficiency):
https://ocr.docketalarm.com/cases/PTAB/IPR2018-00425/Inter_Partes_Review_of_U.S._Pat._7893655/docs/05-01-2019-Board/Hearing_Transcript-51-Hearing_Transcript.pdf

I could not retrieve the FWD's disposition (which claims were held unpatentable/cancelled/amended). The Google Patents Legal Events show an IPRC certificate (K1) issued Oct. 24, 2019 for IPR2018-00425, which indicates at least one claim was cancelled or amended, and show that maintenance fees were paid at 8 and 12 years (Aug. 2018, Aug. 2022) — i.e., the patent was maintained after the certificate, consistent with some claim scope surviving. The element-by-element analysis below is my independent § 103 assessment, not a report of the Board's holding.

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4. The primary ground: claims 1 and 2 over Veselic '708 in view of Vyssotski

4.1 What each reference discloses

US 2004/0164708 A1 (Veselic) — a power supply for a portable device in which an op-amp (52) compares a reference voltage V_REF against a resistor-divided (R5/R6) version of the system-node voltage, and drives the gate of a pass transistor (Q3) between the system node and the battery, varying its drain-source resistance to limit battery charge current whenever the scaled system voltage would fall below V_REF. Veselic expressly describes "restrict[ing] the current through Q3 by increasing its drain-source resistance," and the values of R5 and R6 are "established simply by the need to scale the V_BUS value to the V_REF value" (Veselic ¶¶0077–0080, ¶0078). This is the '655's core teaching, verbatim, one year and more before the critical date.

US 2004/0019815 A1 (Vyssotski) — teaches that the reference voltage used by a power supply can be received from the electronic system/load and varied according to the load's operating state (e.g., a decoder produces different reference levels for different power modes) (Vyssotski ¶¶[0014], [0061]).

4.2 Claim chart — claim 1

Motivation to combine (KSR-compliant):

1. Same field, same problem, same solution space. Both are power-management circuits for battery-powered portable devices; both address the problem of a battery dragging the system rail down during charging.
2. Veselic itself supplies the reason. Veselic recognizes (¶86 in the published application) that portable devices have different operating modes with different minimum supply voltages, yet regulates to a fixed V_REF. Vyssotski supplies precisely the missing piece — a system-sourced, mode-dependent reference — so the combination is the application of a known technique (programmable reference) to a known device (Veselic's comparator/limiter) that is ready for improvement. That is KSR's fourth rationale.
3. Predictable result, no change in principle of operation. Substituting Vyssotski's decoder-produced reference for Veselic's fixed V_REF keeps the same op-amp servo loop and adds only the ability to lower V_SYS in low-demand modes. Both references are analog voltage-mode control loops — no incompatibility.
4. Obvious to try. With only two recognized design choices for the reference source (fixed vs. system-programmable) and a finite, identified set of modes (sleep/idle vs. RF-active), the POSA's path is bounded and the expectation of success is high.

4.3 Claim 2

Claim 2 requires generating output power "in a manner such that said output power has a higher current and a lower voltage than power provided by said external power source" — i.e., a step-down (buck) conversion with current gain. See § 5 below; this limitation is supplied by Kranzen (or by the TI datasheets, or by the '655's own admission about half-bridge converters).

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5. The primary ground for claims 2–11: Veselic '708 + Vyssotski + Kranzen

US 7,570,020 (Kranzen) discloses a switching-regulator-controller-based (buck) power supply that down-converts an external source (the reference discusses a "car adapter") to a regulated Vdd, a battery charger circuit, and a load-sharing/voltage-regulating arrangement that maintains the system node while charging a battery.

5.1 Claim 3 chart (the "USB-compliant circuit" claim)

5.2 Claims 4, 6, 7, 9 (switch-mode supply that converts battery power back through the same inductor/output node)

• Kranzen teaches the supply can be powered from the battery (Kranzen 5:23–26, describing down-conversion of battery voltage Vbatt to ~3.0 V at node N4 when no external source is attached) and that the converter output feeds the load.
• Alternative/secondary support: US 2006/0022640 A1 (Frith) (a power supply circuit for a portable battery-powered device, § 102(e) as of July 26, 2004) and, per ZTE's second petition, White '555 (a forward-converter switch-mode supply converting a 12 V battery output to a 5 V supply through an inductor to a load) and Shum (laptop/portable powered by a battery).
• The TPS62000 datasheet (Sep. 2003) independently teaches a switch-mode DC‑DC converter IC operating from a one-cell Li-ion battery to power a system load — and the '655 specification itself identifies the TPS62000 as its system power supply IC, describing its FB pin and its 1.8 V minimum input and PFM mode. A reference that the patent names as the preferred commercial part is quintessentially prior art for the function attributed to it.
• Motivation: The '655 specification's own stated rationale is efficiency — it explains that linear-mode conversion dissipates up to 50% of input power as heat and that "less power is available to the electronic system," and that handheld systems "increasingly need more power to function." A POSA seeking exactly that benefit would look to switch-mode converters, which the art (Kranzen; TI datasheets; US 6,300,744 "High-efficiency battery charger"; US 6,031,359 "Digitally controlled switch mode power supply") already supplied.

5.3 Claim 5 (output-node voltage fed back to the IC; IC adjusts the node voltage)

• Veselic '708's op-amp/divider network is a feedback loop that sets the node voltage; and Kranzen's regulator is a closed-loop voltage regulator.

• Independently, the TI bqSWITCHER and TPS62000 datasheets disclose FB pins used for "output voltage analog feedback adjustment" — and the '655 specification admits precisely this:

  "The IC 212 is manufactured with the FB pin in order to provide for output voltage analog feedback adjustment. In the illustrated embodiment, the FB pin connection is such that the output node of the circuitry 200 (the V_SYS node) is also the node of the FB pin…"

  A claim element that the specification describes as a pre-existing feature of an off-the-shelf prior-art IC is, without more, obvious. This is close to an anticipatory admission for claim 5 purposes.

5.4 Claim 10 (the switch is a semiconductor switch)

Veselic '708's Q1/Q3 are semiconductor transistors; Kranzen's switching regulator uses MOSFETs; US 6,300,744 (Siliconix) and US 6,741,066 (O2Micro) are drawn to semiconductor power switches in chargers. Selecting a FET as the pass element is the paradigm of an obvious design choice, and the '655 specification itself calls FET 252 a "semiconductor switch."

5.5 Claim 11 (turn the switch off when charging is disabled)

• Shum (per ZTE's second petition, element 188: "Shum Figure 1 discloses an embodiment that supports disabling charging") and the Veselic '707 adaptive-charge-rate reference (charge enable/terminate control) both teach disabling charge.
• US 2004/0239294 A1 (Veselic) and US 2004/0251878 A1 (Veselic) are directed to handling charging state/USB charging in a mobile device.
• EP 0 752 748 A1 (STMicro) ("Multiple function battery charger, self-configuring as supply voltage regulator") teaches reconfiguring the charger's function, which necessarily includes disabling the charge path.
• Motivation: the '655 specification says the CH_EN signal is fed to the CEnot pin of IC 212 and the EN pin of IC 220 — i.e., the enable/disable signal is already present in the admitted prior-art ICs. Gating the isolating FET with the same signal is a routine, predictable use of a known control signal with no change in principle of operation.

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6. Alternative / secondary grounds using other references on the page

These are not necessary to invalidate the claims, but they are useful as independent grounds and as evidence of the breadth of the art.

Ground B — Power-sharing as the "reason to restrict battery current." Veselic '708's teaching is corroborated by a dense § 102(b) body of power-priority art on the face of the patent:

• US 6,118,254 (Compaq) — "Battery charge control architecture for constant voltage maximum power operation": reduces battery charge current to hold up system voltage.
• US 6,222,347 (Apple) — charging the battery using the dynamically determined power available after accounting for power consumed by sub-systems: this is a dynamic, system-demand-aware allocation, i.e., claim 1's core, without needing Vyssotski.
• US 5,939,862 (Dell) — adaptive power battery charging apparatus.
• EP 0 623 985 A1 (SGS‑Thomson) — literally titled "Power Sharing detector."
• EP 0 752 748 A1 (STMicro) — a charger that self-configures as a supply voltage regulator for the powered apparatus.
• US 6,100,664 (Motorola), US 6,188,199 (Eldec), US 5,432,427 (Chiang) — charge control prioritizing the load.

Combining any of Compaq '254 or Apple '347 with Vyssotski (for the mode-dependent system-sourced reference) yields claim 1 with a second, independent motivation narrative: the POSA would combine because both references are directed to the identical problem of allocating a limited external supply between a load and a battery.

Ground C — Switch-mode efficiency as the driver, using the TI datasheets as primary references. The '655 names the bq24105/bq24115 and TPS62000 as its own ICs and says the switch-mode circuits "run at a high efficiency because they are both switch-mode." A POSA starting from these datasheets plus Veselic '708 (isolation/limiting switch) plus Vyssotski (dynamic reference) arrives at claims 1, 3, 5, 8 without any other reference. Because these datasheets were publicly available in 2003–2004 and expressly describe the IC+inductor+FB-pin combination, they carry significant weight against claim 5 and against the "greater magnitude" limitation.

Ground D — The Shum / White '220 / White '555 combination. As charted by ZTE's second petition, this combination supplies the claims 4/6/7/9 switch-mode supply-back-to-the-system limitations. Caveat: this petition was denied institution (General Plastic, procedural), so it has no adjudicative weight — it is only a template, and its merits were never reached.

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7. KSR rationales, consolidated

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8. Anticipated counterarguments and how they fare

The strongest non-obviousness case appears in the Fernald declaration filed by Patent Owner in IPR2018-00426 (https://www.docketalarm.com/cases/PTAB/IPR2018-00426/Samsung_Electronics_Co._Ltd._v._Fundamental_Innovation_Systems_International_LLC/docs/04-11-2018-Patent_Owner/Exhibit-2001-Ex_2001___Fernald_Declaration.pdf) and the '655 Patent Owner's Preliminary Response (quoted at https://ptacts.uspto.gov/ptacts/public-informations/petitions/[1505416](/patent/1505416)/...):

1. "Kranzen's 12 V car-adapter premise is unsupported." PO argued Kranzen never states its input voltage, and 5 V USB car adapters existed. Strength: moderate. This attacks the "greater magnitude than said external power" limitation on a "necessarily present" standard (Par Pharmaceutical v. TWI, 773 F.3d 1186). It is a real problem for a Kranzen-only mapping of claims 2/3/8.
   Rebuttal: don't rest the current-gain limitation on Kranzen's unstated input voltage. Use (a) the TI bqSWITCHER/TPS62000 datasheets, which disclose switch-mode IC + inductor topologies with efficiency curves and expressly teach current handling beyond the input limit; and (b) the specification's own admission that switch-mode circuitry "is capable of providing a greater output current than the input current." Also, Veselic '708 + Vyssotski + a step-down regulator from Frith '640 provides an independent path.

2. "Kranzen's cited passage relates to battery→load, not external→battery." Strength: weak-to-moderate. Kranzen also describes regulated Vdd (≈4.2 V) for battery charging from the external source, so the mapping in § 5.1 is not limited to the battery-powered passage.

3. "Combining Veselic with Vyssotski decouples the reference from the input voltage, contrary to Veselic." Strength: weak. No reference teaches away — Veselic's fixed reference is a design limitation, not a stated requirement, and Veselic ¶86 acknowledges differing mode requirements. Improvement of a suboptimal parameter is not teaching away.

4. "Vyssotski's processor power modes are insufficient for Veselic's system / combination increases heat dissipation." Strength: weak. Heat dissipation is a consequence of the linear implementation, and the whole point of adding the switch-mode converter (Kranzen/TI) is to reduce it. This argument also cuts against the patent's own specification, which disparages linear-mode heat loss.

5. "No motivation because Kranzen already solves the minimum-voltage problem via load sharing." Strength: weak. A reference need not be improved; the motivation can come from any of the five KSR rationales plus the POSA's own knowledge. Kranzen's load-sharing teaches the very result claimed (protecting the system rail), which supports rather than negates the combination.

6. Objective indicia. No evidence of secondary considerations appears in the materials available to me. The patent's specification frames its benefit as USB compliance, and if FISI were to argue commercial success or industry adoption, the nexus is problematic: the alleged benefit flows from the op-amp current-limiting loop that Veselic '708 already discloses, so the evidence would relate exclusively to a feature present in the prior art (cf. Yita LLC v. MacNeil IP LLC, 69 F.4th 1356 (Fed. Cir. 2023)). Patentability here also cannot rest on compliance with an external standard, as the case law generally holds that satisfying an industry specification does not confer non-obviousness where the components are known.

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9. Claim-by-claim bottom line

Aggregate assessment: Claims 1, 5, 10, and 11 are the most vulnerable — claim 1 because Veselic '708 + Vyssotski tracks it limitation-by-limitation, and claims 5/10/11 because the specification itself describes the corresponding structure as a pre-existing feature of off-the-shelf prior-art parts. Claims 2 and 3 (and claim 8's counterpart) turn on the "current of greater magnitude than said external power" limitation, which is the narrowest and most contestable element and which the Patent Owner successfully attacked as applied to Kranzen specifically in the parallel '173 proceeding.

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10. Explicit uncertainties and things I could not verify

1. The disposition of IPR2018-00425. I confirmed the FWD date (July 2, 2019), the panel, the grounds asserted, the July 6, 2018 institution, and the Oct. 24, 2019 IPR certificate (K1). I could not retrieve the FWD text or the certificate's specific disposition. I therefore do not represent which claims were cancelled, amended, or confirmed, and the analysis above is my own § 103 assessment rather than a report of the Board's outcome.
2. Current claim scope. If the certificate cancelled or amended claims, the claims displayed on Google Patents may not reflect the surviving scope. The apparent absence of "[Cancelled]" markers, plus the payment of maintenance fees through the 12th year, suggests some scope survived — but this is inference, not confirmation.
3. No 2026 CAFC activity found. Consistent with the earlier-generated summary, I found no Federal Circuit appeal or 2026 docket activity naming this patent. Absence of evidence, not proof of absence.
4. Date disqualification. As noted in § 2, the Maxim app note (Aug. 25, 2006) and the Summit press release (Feb. 21, 2006) are listed on the patent's face but postdate the Dec. 13, 2005 priority date and cannot serve as § 102 prior art. If a later-issued family member with a different effective date is being analyzed, this would need to be re-checked.
5. IPR2018-01076's merits. That petition was denied on General Plastic procedural grounds, so its Kranzen/Veselic/Vyssotski and Shum/White combinations were never adjudicated. Cite them as templates and motivation evidence only.