TPS3813: Not able reset the Microcontroller

Rohal

Intellectual 495 points

Part Number: TPS3813

Tool/software:

Dear Team,

We are using TPS3813 ic as external watch dog for my microcontroller, and its working fine as per expectation,

it reset the MCU if my system working fine(In testing put a while(1); in firmware and its resset by TPS3813 ),

but we found if MCU goes Hang (stuck some where) TPS3813 also goes Hang mean it not reset my MCU, now I'm how its possible that TPS3813 ic didn't work.

as per attached schematic pin 6 RST connected with MCU reset. we observe this strange behavior on oscilloscope also.

Please suggest what wrong with circuit what else we can try to over cum this type of problem

10 months ago

0 Masoud Beheshti61 10 months ago

TI__Mastermind 18041 points

Hello, our team will respond shortly. Thanks.

0 Joshua Garcia 9 months ago in reply to Masoud Beheshti61

TI__Genius 11550 points

Ho Rohal,

Could you provide a scope capture containing the VDD (pin 4), RESET (pin 6), and WDI (pin 1) voltages when the TPS3813 IC is not working properly?

Thanks,
Joshua

0 Rohal 9 months ago in reply to Joshua Garcia

Intellectual 495 points

VDD = 3.3V

RESET = 3.3V

WDI = 0V (because MCU Hang up)

0 Joshua Garcia 9 months ago in reply to Rohal

TI__Genius 11550 points

Hi Rohal,

Could you remove R8 and replace it with 0 ohm resistor. Also if you could place a 10kOhm resistor between the WDI pin and ground. The reason I asked for the scope capture is so that I can see whether there is some floating/spikes on the WDI that are causing the watchdog to not reset, I would also get to confirm if the device is acting within the proper window timing period.

Thanks,
Joshua

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TPS3813: Not able reset the Microcontroller