TPS3820-Q1: the watchdog time out spec changed after high temperature test

Aki Li

Part Number: TPS3820-Q1

Tool/software:

My customer reported an urgent issue that they found TPS3820-Q1's ttout (Watchdog time out) changed permanently after they implemented the high temperature test (100 degree).

In the below waveform, reset was triggered after WDI keeping low for 178ms. We told customer that the timing was still within our datasheet spec, but before the high temp test, no reset event occurred with the same WDI timing. The phenomenon occurred at every parts they tested.

Could you please help explain the possible reasons?

CH1:WDI CH2: /Reset

over 1 year ago

0 Joshua Garcia over 1 year ago

TI__Genius 11650 points

Hi Aki,

To help solve this issue could you please help provide the below information:

What is the exact OPN being used here?
Could you provide a schematic?
Could you provide scope captures that include the VDD and MR pins aswell
How many parts were tested?
If you power cycle the device does the timing remain at 178ms? (Is it burning in?)

Thanks,
Joshua

0 Aki Li over 1 year ago in reply to Joshua Garcia

TI__Genius 9755 points

Joshua,

TPS3820-33QPDBVRQ1.

They have tested 10pcs, with the same results. After power cycle, it still remained the same. VDD was stable during the test.

0 Joshua Garcia over 1 year ago in reply to Aki Li

TI__Genius 11650 points

Hi Aki,

I have moved this thread over to email.

Thank you,
Joshua

Power management

Power management forum

TPS3820-Q1: the watchdog time out spec changed after high temperature test