TPS25942A: Reverse polarity protection circuit

Hi chentsu chung,

Can you please share the part number of Signal Diode you used. What is the reverse polarity voltage applied during testing? Have you measured the leakage current through the Signal Diode during this test.

Best Regards,
Rakesh

Hi Rakesh,

1. The diode is BAV20W(www.diodes.com/.../Ds12024.pdf)
2. Use 12V for reverse polarity testing
3. According to spec, the reverse currenr is 0.1uA@25degreeC, we don't have suitable equipment to measure it.

BTW, we have tried to remove R1/R2/R3, and still see -0.7V; and tried to add resistor in series whith signal diode, and still see -0.7V.

Please help on these 3 questions, thank you very much!
1. the absolute min. voltage is -0.3V(IC-IN to IC-GND) in spec. so the -0.7(IC-IN to IC-GND) will damage IC or not?
2. How the -0.7V comes out? the leakage current of signal diode? Internal protection diode? Or anything else?
3. How to extinguish the -0.7V

Hi chentsu chung,

Thanks for the inputs.
I will verify the path for leakage on bench and clarify you.

Best Regards,
Rakesh

Hi Rakesh,

One more testing update for your reference.

Modify R1+R2+R3 to 3KOhm, according to 0.1uA reverse current, efuse GND-Vin shoud be 0.3mV, but still got 0.7V on GND-Vin.
Looking forward for your update, thank you very much!

Best regards,
C.T.

Hi chentsu chung,

I have verified on EVM and observed only -0.2V between IC-IN to IC-GND. Not sure, what we are missing here..
Are you checking on TI-EVM or made any board?

Best Regards,
Rakesh

Hi Rakesh

Can you please share the single Diode that you used, and the resistance value which you choosed in the verification?

Best Regards,

Tim Hsu