Power Integrations, Inc. v. On Semiconductor Corporation, 396 F.Supp.3d 851

Background

Power Integrations (PI) and ON Semiconductor (ON) are adversaries in consolidated patent litigation; each asserts multiple patents against the other and also asserts invalidity/counterclaims.
PI asserts seven patents (including the ’079, ’876, ’471, ’623, ’533, ’457, ’119); ON asserts eight patents (including the ’624, ’709, ’933, ’908, ’862, ’221, ’272, ’601).
ON moved for summary judgment on six discrete issues (indefiniteness, damages period/pre‑suit notice, IPR prosecution disclaimer, claim limitation "fixed switching frequency," anticipation by Krupka, and adequacy of infringement evidence for an amended claim); PI moved on eight issues (issue preclusion/privity, IPR estoppel, anticipation by PI’s SMP3 product, and non‑infringement/insufficiency of ON’s evidence on several ON patents, plus willfulness).
Procedural complexities: overlapping prior district‑court decisions and PTAB IPRs (some Final Written Decisions later vacated by the Federal Circuit as time‑barred), and a prior Fairchild litigation involving many of the same patents; ON acquired Fairchild during the dispute timeline.
The court resolved the parties’ cross‑motions in part: it granted ON summary judgment on indefiniteness for three PI patents and granted PI summary judgment of non‑infringement on two ON patents and no willful infringement; other claims survived summary judgment.

Issues

Issue	Plaintiff's Argument (PI)	Defendant's Argument (ON)	Held
Indefiniteness of PI’s ’623, ’533, ’457 claims	Claims are definite (opposed implicitly)	Court previously held claims indefinite	Granted for ON (claims invalid)
Damages period / pre‑suit notice (35 U.S.C. §287)	For some patents PI contends it gave actual notice (e.g., June 16, 2014 email) or that §287 doesn't apply to method claims (’471)	ON argues lack of marking/notice limits damages to filing date	Mixed: granted for ON as to ’119 (no notice); denied as to ’079 and ’876 (factual dispute over notice); denied as to ’471 (§287 inapplicable to method claims; ON waived alternate argument)
Prosecution disclaimer from IPR for ’079 (claim scope)	PI: not bound; disclaimer not applicable here	ON: PI disclaimed scope during IPR so accused products fall outside claims	Denied for ON; court finds prosecution disclaimer inapplicable (argument not raised at claim construction and PTAB rejected PI’s position; PTAB decision vacated)
"Fixed switching frequency" limitation (’079)	PI: construction allows jittering; earlier judge’s construction adopted by PI	ON: accused products have time‑varying frequency and thus do not meet limitation	Denied for ON; court applied prior district construction for motion and found factual disputes remain (expert evidence)
Anticipation of PI’s ’471 by Krupka	PI: Krupka does not disclose required feedback signal (expert support)	ON: Krupka anticipates claims	Denied for ON; ON failed to show anticipation by clear and convincing evidence (no expert tying POSITA understanding)
IPR estoppel (35 U.S.C. §315(e)(2))	PI: ON should be estopped by IPRs	ON: IPRs were instituted but FWDs vacated	Denied for PI; estoppel requires a final written decision and vacatur removes that effect
PI’s assertion of issue preclusion/privity (ON ≈ Fairchild)	PI: ON is successor or controlled Fairchild litigation and thus precluded from relitigating validity	ON: privity follows the product; accused products are legacy‑ON, not acquired Fairchild products; ON did not control earlier suits	Denied for PI; court finds no privity for nonacquired products and no sufficient control over prior litigation
Non‑infringement of various ON patents (’601, ’272, ’933, ’624)	PI: its products do not meet limitations (e.g., regulate output voltage, temperature compensation, memory circuit, receive current reference)	ON: relies on contentions, datasheets, expert reports (Madisetti)	Mixed: Granted PI re: ’601 and ’272 (ON’s expert relied on undisclosed Teardown; excluded); Denied re: ’933 and ’624 (genuine factual disputes remain)
Willful infringement by PI	PI: ON lacks evidence of pre‑suit notice to support willfulness	ON: points to communications (Sept. 2014) but provides no admissible supporting evidence	Granted for PI (no willfulness)

Key Cases Cited

Celotex Corp. v. Catrett, 477 U.S. 317 (summary judgment standard)
Nautilus, Inc. v. Biosig Instruments, Inc., 572 U.S. 898 (indefiniteness principle)
Amsted Indus., Inc. v. Buckeye Steel Castings Co., 24 F.3d 178 (definition of actual notice under §287)
Funai Elec. Co. v. Daewoo Elecs. Corp., 616 F.3d 1357 (scope of notice to other models)
K‑TEC, Inc. v. Vita‑Mix Corp., 696 F.3d 1364 (notice and related products)
Aylus Networks, Inc. v. Apple Inc., 856 F.3d 1353 (prosecution disclaimer doctrine)
Omega Eng’g, Inc. v. Raytek Corp., 334 F.3d 1314 (prosecution disclaimer prevents recapture)
Biogen Idec, Inc. v. GlaxoSmithKline LLC, 713 F.3d 1090 (narrowing by prosecution history disclaimer)
Roemer v. Peddie, 132 U.S. 313 (limitations inserted during prosecution bind patentee)
Schriber‑Schroth Co. v. Cleveland Trust Co., 311 U.S. 211 (claims read with reference to rejected claims)
Amazon.com, Inc. v. Barnesandnoble.com, Inc., 239 F.3d 1343 (claims must be interpreted consistently for validity and infringement)
Taylor v. Sturgell, 553 U.S. 880 (nonparty preclusion exceptions)
Kloster Speedsteel AB v. Crucible Inc., 793 F.2d 1565 (privity following transferred assets producing infringing products)
Brunswick Corp. v. Chrysler Corp., 408 F.2d 335 (successor liability/privity for transferred business producing the same products)
International Nutrition Co. v. Horphag Research, Ltd., 220 F.3d 1325 (privity limited to transferred property rights)
Munoz v. County of Imperial, 667 F.2d 811 (privity depends on rights obtained through transfer)
Microsoft Corp. v. i4i Ltd. P’ship, 564 U.S. 91 (clear and convincing standard for invalidity)
Power Integrations, Inc. v. Fairchild Semiconductor Int’l, Inc., 904 F.3d 965 (prior district and appellate rulings addressing "fixed switching frequency")