TSMC GaN Foundry Exit July 2027: A Last-Time-Buy and Second-Source Map for 2026 GaN Buyers

TSMC will close its GaN-on-Si foundry on 31 July 2027 (per LEDinside’s coverage of TSMC’s customer notification and the SemiWiki analysis, accessed June 2026). The fabless GaN vendors most affected — Navitas, EPC, Power Integrations — have moved at very different speeds. Navitas signed a 200 mm GaN-on-Si production agreement with PSMC in July 2025. EPC has publicly indicated VIS as its 8-inch foundry partner. Power Integrations has not publicly disclosed an alternative foundry path as of June 2026, which makes its TSMC-foundry parts the highest last-time-buy risk in this transition. GlobalFoundries licensed the GaN-on-Si IP from TSMC and is targeting end-2026 production at its Vermont fab. TSMC GaN exit 2027 Navitas alternative decisions are 2026 work — the parts you stockpile or re-qualify this year define what your 2027 line actually runs on.

We see this conversation almost weekly. A charger or industrial PSU OEM, somewhere between 100 and 2,000 boards a month, sends us their power-stage BOM. Line item: GS66508T, Navitas NV6131, or a Power Integrations InnoSwitch part with a GaN switch inside. Question: “Can you cover us into 2027?” The honest answer depends on which fabless vendor designed the part, what they have publicly disclosed about their post-TSMC roadmap, and how much of your design’s electrical envelope tolerates a fab transition at the silicon level.

What changed and when

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TSMC has been a central node in GaN power transistors for roughly a decade — many fabless vendors used its 200 mm GaN-on-Si line in Hsinchu for high-volume production. Per the SemiWiki analysis, TSMC concluded GaN did not align with its long-term capital allocation. Customers were notified through 2024–2025 of a hard 31 July 2027 production end date.

The compressed timeline:

That last row drives 2026 procurement behavior. Any TSMC-foundry GaN part needs either a confirmed second-source path through 2027 or a stockpile sized to bridge into the new fab’s qualified output. Both decisions are 2026 work.

Per-vendor migration status

Navitas → PSMC (most disclosed)

Navitas Semiconductor announced in July 2025 a 200 mm GaN-on-Si production agreement with Powerchip Semiconductor Manufacturing Corporation (PSMC) of Taiwan (per the Navitas PR via financialcontent.com). PSMC has prior experience with non-silicon process integration on its 8-inch lines.

This is the cleanest disclosure of the four. The remaining uncertainty is process equivalence: PSMC’s GaN-on-Si is positioned by Navitas as substantially equivalent to the TSMC process at the device level, but production-yield and field-reliability data for parts manufactured at PSMC are not yet public as of June 2026. Treat this as vendor-stated equivalence pending real-world data.

EPC → VIS

Efficient Power Conversion (EPC) has publicly indicated Vanguard International Semiconductor (VIS) as its 8-inch foundry partner for the post-TSMC era. EPC’s portfolio is concentrated in lower-voltage GaN — 80 V to 200 V, with some 350 V parts — used in motor drives, lidar, and small-form DC-DC. Public disclosure is less granular than the Navitas/PSMC PR; track EPC’s investor communications and PCNs through late 2026.

Power Integrations → undisclosed (highest LTB risk)

Power Integrations has not publicly disclosed an alternative foundry path for its GaN switches as of June 2026. PI integrates GaN switches into its InnoSwitch and HiperPFS controller families — these are integrated controllers with internal GaN switches, not discrete transistors, which means a foundry transition has knock-on effects across the controller silicon as well. For 2026 procurement planning, PI’s TSMC-foundry GaN parts are the highest last-time-buy risk in this transition until and unless PI discloses a clear post-TSMC path.

Innoscience and Infineon CoolGaN (independent IDMs)

Innoscience never depended on TSMC. The company runs 8-inch GaN-on-Si lines in Suzhou and a newer Zhuhai facility (per the Innoscience corporate pages) under a vertically integrated IDM model. Innoscience parts are not pin- or electrically-compatible drop-ins for Navitas or EPC silicon by default — package, RDS(on), QG, and derating curves differ — and any cross-reference must be done at the schematic level with bench validation.

Infineon has been an independent GaN IDM since the late 2010s, with high-volume GaN-on-Si production at its Villach (Austria) and Magdeburg (Germany) 200 mm fabs (per the Infineon CoolGaN HEMT portfolio page). Like Innoscience, Infineon CoolGaN is unaffected by the TSMC exit. The GS66508T → CoolGaN transition is covered in our GS66508T sourcing guide.

GlobalFoundries Vermont (TSMC IP licensee)

GlobalFoundries licensed the GaN-on-Si IP from TSMC and has publicly targeted end-2026 production at its Burlington (Vermont) fab. This is the U.S.-domestic answer and is interesting for U.S. defense and CHIPS-Act-aligned customers more than for general commercial OEMs. Production timing slips are common in fab transitions — treat end-2026 as a target, not a commitment, and confirm against GlobalFoundries press releases closer to the date.

What this means for your 2026 BOM

Three buyer scenarios cover most of the conversations we have.

Scenario A — You have GS66508T or Navitas NV6131 in production already. Two-track work. Track one: size a last-time-buy stockpile to bridge from your 2026 buy through whenever your second-source qualification is ramped — typically a 12–24 month consumption equivalent for our customer profile. Track two: open a second-source qualification on Innoscience or another IDM-sourced 650 V GaN part, on a schedule you can finish before mid-2027.

Scenario B — You’re starting a new GaN design in 2026. Avoid TSMC-foundry-dependent parts where possible. Default to vendors with a disclosed post-TSMC path (Navitas/PSMC) or to IDMs that never depended on TSMC (Innoscience, Infineon CoolGaN). On Power Integrations parts, weigh the integration value (driver + GaN co-packaged) against the higher LTB risk.

Scenario C — You’re qualifying a new PSMC- or VIS-fab part as a second source. The vendor will state device-level equivalence. Plan a re-qualification effort on your bench: thermal cycling, switching-loss characterization, gate-drive margin, short-circuit ride-through. The equivalence claim is a starting point, not a substitute for board-level data on the parts you’ll actually ship.

For workflow on weighting stockpile vs. drop-in vs. platform-migrate decisions, our supply chain diversification framework is the methodology overlay; the SiC vs GaN decision guide walks topology trade-offs; the electronic component lifecycle explainer is the lifecycle primer.

Decision matrix: vendor by vendor

LTB risk class is our procurement-side reading as of June 2026 and may shift as vendor disclosures evolve. Confirm against vendor PCNs and investor communications before any major stockpile decision.

AEC-Q101 reality: re-qualification is the buyer’s risk

AEC-Q101 qualification is granted at the part-process level. Strictly, a part qualified at TSMC’s 200 mm GaN-on-Si line is a different qualification entry than the same part number manufactured at PSMC’s or VIS’s 200 mm line — even when the vendor states process equivalence.

Vendors are running re-qualification programs in parallel with the foundry transition. When a vendor publishes a PCN announcing fab transition for a given part, the AEC-Q101 status of post-transition silicon should be in the PCN. If it is not, that is the question your supplier-quality engineer should be asking before any second-fab parts go through your reflow.

If you ship into Tier 1 automotive, your customer will ask for the post-transition AEC-Q101 report. Bake that into the second-source qualification plan now, not in Q4 2026 when the parts arrive. (Cosolvic does not perform AEC-Q101 audit certification — that work belongs to vendors and accredited test labs; we surface what is in vendor PCNs and source NOS or sample inventory against your design’s qualification status.)

How small-batch buyers should respond

Cosolvic operates as a Shenzhen-based independent sourcing specialist for the 100–5,000-piece-per-month volume tier. Three lanes apply here.

Lane 1: NOS last-time-buy via broker channels. GS66508T (legacy GaN Systems / pre-Magdeburg CoolGaN production) and Navitas NV6131-class TSMC-fab silicon are available via the broker network in volumes typical of a 6–18 month bridge stockpile. Authenticity inspection (visual, marking, decap on request via partner labs) and our 100% authenticity-or-full-refund guarantee apply. Power Integrations integrated GaN parts are also broker-available; given the higher LTB risk, tighter quality discipline applies on those orders.

Lane 2: Innoscience samples for fit testing. Innoscience’s volume sales channel for >5,000-reel orders is direct or through their authorized network, not Cosolvic. For design-in fit testing — typically 50 to 500 pieces of a candidate cross-reference — Cosolvic can sample-quote on a 5–7 day window. Use this lane for Scenario A/C qualification work, not production volumes.

Lane 3: Infineon CoolGaN as the IDM-sourced alternative. The IGOT60R070D1 cross-reference for GS66508T is the cleanest IDM-sourced 650 V path, with the caveat that RDS(on) is higher and the package differs — see the GS66508T sourcing guide. Cosolvic quotes CoolGaN through the broker network for the same NOS-style volumes as Lane 1.

FAQ

When exactly does TSMC stop manufacturing GaN?

31 July 2027, per TSMC’s customer notification covered by LEDinside and the SemiWiki industry analysis. After that date, no new GaN-on-Si wafers will start at TSMC; in-flight inventory continues to ship until depleted.

Is GS66508T affected?

Indirectly. GS66508T is now an Infineon CoolGaN family part since the GaN Systems acquisition, and Infineon manufactures CoolGaN at its own Villach and Magdeburg 200 mm fabs — independent of TSMC. Legacy GaN Systems-marked broker inventory may have originated at TSMC; current production is at Infineon. See the GS66508T sourcing guide.

Can Innoscience parts drop in for Navitas?

No, not as a default. Pin-out, package, RDS(on), QG, and derating curves differ between the two vendors. Innoscience is a credible second-source candidate at the architectural level — independent IDM, unaffected by the TSMC exit — but any cross-reference requires vendor-brief comparison and bench validation. We can sample-quote Innoscience candidates for the validation effort.

How big should my last-time-buy be?

Enough to bridge from your 2026 buy through second-source qualification ramp. For most charger / PSU / industrial OEMs in our customer profile, that is a 12–24 month consumption equivalent. Sizing depends on monthly burn rate, qualification speed, and packaging shelf-life constraints (GaN power transistors are generally not shelf-life sensitive; moisture-sensitive packaging is).

Is GlobalFoundries Vermont a real option for 2026?

Not for 2026 production — the fab is targeting end-2026 for first production, and any fabless customer using the Vermont line will be in qualification ramp through 2027. For 2028+ designs aligned with U.S.-domestic supply mandates, it becomes interesting. For 2026 BOM decisions, it is not yet an executable second source.

What about Power Integrations specifically — should I switch vendors?

Not necessarily. PI’s integrated GaN controllers (InnoSwitch, HiperPFS) carry real design value because the driver and switch are co-packaged. The conservative position for 2026: keep PI in your design, watch PCNs and investor communications for foundry disclosures, and build a larger LTB cushion than for vendors with disclosed post-TSMC paths.

For parts headed into production, who verifies them before they ship matters as much as the part itself. How Cosolvic operates covers our inspection process, counterfeit refund policy, and why we work as an independent distributor rather than a franchise reseller.

Closing

The TSMC GaN exit is one of the cleaner forced-migration events in power semiconductors — the date is hard, the vendor responses are mostly public, and the second-source landscape is real. What it costs procurement teams is 2026 calendar time on stockpile sizing, second-source qualification, and AEC-Q101 paperwork. Letting any of those slip past Q3 2026 leaves you negotiating a 2027 supply gap from a worse position.

If you want a sourcing-side conversation on a specific GS66508T, Navitas, or Power Integrations part — bridge stockpile, Innoscience cross-reference samples, or CoolGaN broker quote — Cosolvic’s quote desk handles those weekly. We are honest about which lanes we fulfill (broker NOS, Innoscience design-in samples, Infineon CoolGaN broker) and which we don’t (Innoscience volume direct, authorized Infineon allocation). Send the part number and the monthly volume; we’ll come back with what is real.