Automotive microcontroller supply has improved through the second half of 2026, but the recovery is uneven. General-purpose MCUs on mature 90nm and 130nm nodes are now quoting at 18 to 22 weeks, down from more than 40 weeks at the 2023 peak.
Where it is still tight
- 40nm automotive MCUs used in body control, gateway and chassis applications remain on allocation at three major manufacturers.
- Parts qualified to AEC-Q100 Grade 0 continue to carry the longest lead times.
- Manufacturers are prioritising existing programme schedules over new business, which pushes new part numbers to the back of the queue.
What it means for a running build
Programmes that are already in production with an approved part number are largely protected. Programmes moving from prototype to series production are the exposed ones: a new part number introduced now can take two quarters longer than its catalogue lead time suggests.
Our desk recommends confirming allocation status at the part-number level rather than the family level, and starting the last-time-buy analysis for any 40nm device with a forecast horizon beyond 2028.
What we are watching
Wafer starts at 40nm automotive capacity have been committed forward, and there is no sign of the second-source capacity that would break the allocation. Until that changes, expect allocation letters rather than lead-time normalisation.