TPS3820-Q1: Reset pin malfunctions

Sam Sun

Part Number: TPS3820-Q1
Other Parts Discussed in Thread: TPS3820

Hi,

This was used for a mass production design.

When applied to new solutions, the feed dog Pulse width change From 10ms to 7ms，But the tw Pulse width at WDI is 100ns in datasheet，7ms>>100ns.

But the RESET happened.Therefore, could you please help what may cause this problem?

over 2 years ago

0 Walter Zollinger over 2 years ago

TI__Expert 7410 points

Hello Sam,

Is there a 1K Ohm resistor between WDI and ground? It is needed to disable the internal WDI pulse. TPS3820 has a push-pull /Reset output and does not need a pullup resistor. Can you remove the /Reset pull up resistor and repeat the experiment?

Best,

Walter

0 Sam Sun over 2 years ago in reply to Walter Zollinger

Intellectual 785 points

Hi Walter，

I am not sure what do you mean by saying that disable the internal WDI pulse?

What should i do for it?

Thanks

0 Walter Zollinger over 2 years ago in reply to Sam Sun

TI__Expert 7410 points

Hi Sam,

A 1k resistor is needed between WDI and ground. It appears to be not populated in the schematic. Is this the case?

Best,

Walter

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TPS3820-Q1: Reset pin malfunctions