What is the difference between STM32L151CBU6 and STM32L151CBU6A? Can they be interchangeably used?

[igamoso]

What is the difference between STM32L151CBU6 and STM32L151CBU6A?

Can they be interchangeably used?

[GLASS]

Some year ago we tried to replace stm32l151rct6 by stm32l151rct6A.

We detected instability, may be due to pll default at startup.

We were surprised that A ref was very quickly NRFND​ (Not Recommanded For New Design).

May be it confirm that A ref was a bad try and was abandoned...

Now all stm32l1 are NRFND.​

May be give a look to L4 or U5...

Not sure that it is pin to pin compatible for your design (you must check), but for sure that​ need rework for SW.

[Peter BENSCH]

There is a technical note TN1176 describing the migration from e.g. the (older) STM32L15xx6/8/B to the (newer) STM32L15xx6/8/B-A and the differences.

Yes, both are already on NRND, but will still be produced until the end of 2031. Nevertheless, as @GLASS​ noted, it makes sense to switch to another family.

Regards

/Peter