TPS65381A-Q1: Output status under SPI abnormal & WD time out

Beida Song

Part Number: TPS65381A-Q1

Tool/software:

Hi Expert,

I am promoting TPS65381A-Q1 to customer. Customer has a question:

If WD time out and SPI is abnormal because of MCU issue, but IGN or CANWU is exceed WU threshold voltage, the output is abnormal under this condition?

3 months ago

0 Michael Hernandez 3 months ago

TI__Expert 5450 points

Hi Beida,

It's a little bit difficult to understand what you are asking here. On this device if the WD is failing the output should be normal but the reset pin should be pulled low repeatedly. Once the threshold is reached the entire PMIC should shutdown but with a voltage on the ign pin the device should try to start up again and repeat this process. Hopefully this answers your question.

Best,

Michael Hernandez

0 Beida Song 3 months ago in reply to Michael Hernandez

TI__Intellectual 800 points

Hi Michael,

Let me clarify my question:

Test Condition:

1. IGN or CANWU reach wake up threshold;

2. WD time out;

3. MCU run out, so PMIC loss the SPI communication;

under this condition, The PMIC will output normally?

0 Michael Hernandez 3 months ago in reply to Beida Song

TI__Expert 5450 points

Hi Beida,

The PMIC is configurable. By default, it will continue to operate normally except for the reset and ENDRV being pulled low. Assuming the reset pulldown was enabled for the watchdog and ENDRV was enabled at all. The PMIC can however be configured to turn off after it enters the reset state a preconfigured amount of times. Hopefully this clarifies how the device operates.

Best,

Michael Hernandez

0 Beida Song 3 months ago in reply to Michael Hernandez

TI__Intellectual 800 points

Hi Michael,

Thanks for your update. Another question: If WD disable, is TPS65381A-Q1 output normal when SPI fails because of MCU issue?

0 Michael Hernandez 3 months ago in reply to Beida Song

TI__Expert 5450 points

Hi Beida,

I believe the PMIC will continue to operate as configured if the WD is disabled and there is a SPI communication issue.

Best,

Michael Hernandez

Power management

Power management forum

TPS65381A-Q1: Output status under SPI abnormal & WD time out