Hello,
I Have a big problem - a customer returned 16 products - this has always happened, but it is becoming frequent now.
The product is based on the obsolete LM3S997 cortex M3 microcontrollers and what we find is the LDO (1.2V) has no output - so the MCU is well, dead.
I need to know why and see if there is any fix. We have lots of the products in the field and we need to have a solution please.
Please please help me, thank you.
Hi Ambrose,
Sorry to hear your problem. As you already understand, the LM3S997 is an obsolete product. We have very little knowledge of this product as our knowledge and support is around the Tiva MCU. Having said that, it is the first time I'm hearing the LDO output is dead. There are several critical erratum about LM3S997 and their variants; mostly around the flash corruption under different circumstances. There is no such errata as I can find about a dead LDO. It seems like there may be some type of EOS (electric over-stress) on the device that might have damaged the device.
Other than the dead LDO, do you see the rest of the pins functioning?
Is the VDD properly supplied to the MCU?
Can you still connect to the devices?
Do you have proper decoupling capacitors on the VDD and VDDC?
Do you know if the flash content is still intact?
I wish I could provide some tips to check. Again, this is a device we don't support anymore and we really have not much knowledge about it.
Below I found the system design guideline and errata related to this device.
