TPS3851: TPS3851G33EDRBR

Part Number: TPS3851

Tool/software:

Hi team,

We have one doubt regarding the MR# pin of the Watchdog IC.

                                          

We designed the IC as mentioned above.

Our observations are as follows

1. We gave 1.8V logic high on SOFT_RESET# pin, then WTD_MR# pin shows 0V as logic low.

2. We gave 0V logic low on SOFT_RESET# pin, then WTD_MR# pin becomes 1.1V logic high. It was an unexpected value of MR# pin since MR# pin has an internal pull-up.

3. After that, we removed Q11, at that time also WTD_MR# pin shows 1.1V logic high.

4. WTD_MR# pin only shows 4.6V logic high value when we mounted 10k pull up on R222.

Why is this MR# pin showing this 1.1V logic high state? Please give a reason behind this strange behaviour.