ADI PDN 26_0046: TSMC Fab 2 & 5 Closure Forces Last-Time-Buy on Legacy-Node Parts

What changed #

Analog Devices published PDN 26_0046 — "Discontinuation of Parts Manufactured in TSMC Fab 2 and 5 in Hsinchu, Taiwan" on 20 August 2026. This is not a routine end-of-life for one device family. The root cause sits upstream at the foundry: TSMC has announced the planned closure of its legacy 6-inch and 8-inch manufacturing facilities, Fab 2 and Fab 5, in Hsinchu, Taiwan, with manufacturing operations expected to cease by the end of 2027.

Because ADI fabricates the affected products there, and ADI states it has been unable to establish a viable alternate source for them, those products must enter the Last Time Buy (LTB) and Last Time Ship (LTS) process. The notice itself is a 32-page document that names the complete set of affected manufacturer part numbers.

Why this notice is different from a normal PDN #

Most product discontinuance notices are ADI-initiated: a part has low demand, a newer device supersedes it, or a process node is consolidated, and a qualified replacement is usually named. PDN 26_0046 is the opposite shape:

• The trigger is a foundry closure, not a product decision. When a fab goes dark, every device routed through it is at risk regardless of its own commercial health.
• No alternate source was found. ADI explicitly says it could not move these products to another line. That removes the usual "qualify the suggested replacement" escape hatch.
• The window is fab-bound, not demand-bound. The hard constraint is TSMC's end-of-2027 manufacturing stop, so the practical last-ship horizon is set by the foundry, not by ADI's inventory preference.

For buyers, the practical meaning is that the affected parts will not reappear through the authorized channel once the window closes. After LTS, the only remaining sources are aftermarket, broker and obsolete-stock channels — exactly where counterfeit and remarking risk climbs.

Which parts are affected #

The scope is precise: ADI parts whose manufacturing is tied to TSMC Fab 2 and Fab 5 in Hsinchu — ADI's legacy 6-inch and 8-inch process lines. The PDN does not target a single product category; it targets a manufacturing route, so the affected list can span multiple analog, mixed-signal and linear families built on those nodes.

The complete affected-MPN list is the 32-page appendix of PDN 26_0046. Do not assume a part is safe — or assume it is discontinued — from its function alone. Confirm each exact ordering code against the official list before making a lifecycle decision. If a part you use is not on the list, this notice does not change its status.

Why buyers should care #

• The clock is the fab's, not yours. Because the driver is a 2027 foundry shutdown, the available LTB/LTS window is finite and shared across every customer depending on these lines.
• No replacement is offered. With no alternate source named, a redesign or qualified aftermarket buy is the only path the notice leaves open for affected parts.
• Secondary-market exposure rises immediately. Obsolete and last-time-buy analog parts are frequent counterfeiting targets — the package looks identical and the die is hard to verify without inspection.
• BOM continuity needs a decision now. Waiting until line-down stock runs out turns a planned last-time-buy into an emergency requalification.

RFQ and sourcing checks #

Practical takeaway #

PDN 26_0046 is a foundry-closure-driven discontinuation: ADI is ending parts built in TSMC Fab 2 and Fab 5 because those legacy fabs close by the end of 2027, and ADI has found no alternate source. If your designs use older ADI analog or mixed-signal parts, the first move is to confirm each exact MPN against the 32-page PDN list — not to guess. For any part that is on the list, open a last-time-buy calculation now, plan for a redesign or qualified aftermarket path since no replacement is named, and tighten authenticity and traceability checks on anything sourced outside the authorized channel.

Sources #

• Analog Devices, Product Discontinuance Notice PDN 26_0046, "Discontinuation of Parts Manufactured in TSMC Fab 2 and 5 in Hsinchu, Taiwan," published 20 Aug 2026. States TSMC Fab 2 and Fab 5 (legacy 6-inch and 8-inch fabs) are planned to cease manufacturing by end of 2027, ADI could not establish a viable alternate source, and affected products enter LTB/LTS; complete affected-MPN list in the 32-page notice. (analog.com PCN/PDN document PDN 26_0046)