TPS2051C: About resistance between OUT pin and GND pin

user3853132

Part Number: TPS2051C

Dear experts，we use TPS2051C to design a charging protection circuit，we use a multimeter(FLUKE,179) to measure the resistance between its OUT pin and GND pin，and find that the resistance will be different. Most IC resistance values are displayed OL (the multimeter range is 0~60MΩ)，it means they are greater than 60MΩ，but there are a few ICs with a resistance value of 30MΩ~50MΩ，is this difference in resistance normal？

What is the correct resistance between OUT pin and GND pin？

I appreciate your great help in advance.

Best regards,

Kevin

over 3 years ago

0 Michael Tan over 3 years ago

TI__Expert 8420 points

Hi ,

It don't have a data to show the resistance between the OUT and GND.

It should open Drian of the output discharge circuit.

0 user3853132 over 3 years ago in reply to Michael Tan

Prodigy 60 points

In addition，the test is not powered on

0 Michael Tan over 3 years ago in reply to user3853132

TI__Expert 8420 points

Hi ,

When device power off the OUT is keep high impedance .

You can't to identify the device is normal or not depend the OUT pin to GND resistance.

If you want to verify the OUT discharge resistance you can disable the device then monitor the discharge resistance whether is 470ohm or not.

0 user3853132 over 3 years ago in reply to Michael Tan

Prodigy 60 points

I get it，thanks.

0 user3853132 over 3 years ago in reply to Michael Tan

Prodigy 60 points

Another question，How much impedance is high impedance？As long as it is mega-level？

0 Michael Tan over 3 years ago in reply to user3853132

TI__Expert 8420 points

Hi,

Yes, it should be mega level.

But there are not detailed data to show you how much the OUT to GND resistance when device out of power.

0 user3853132 over 3 years ago in reply to Michael Tan

Prodigy 60 points

Recently，we found that there are some failed ICs，its resistance between OUT pin and GND pin became Ω-level，so we sampled the resistance of some ICs on the PCBA， and found that a small part of the ICs‘ resistance is lower than others(most ＞ 60MΩ，few 20MΩ~50MΩ).

We can’t judge if this is a normal phenomenon or the IC has some changes.

Another problem，in order to reproduce the failure，we try to overload or short-circuit the IC’s OUT pin，but when the current exceeds the current-limit(500mA)，the IC is protected and cannot fail at all.

How to make it fail？

The schematic is as follow(POWER=5V，P2-3 is the outpout port，240mA max)

0 Michael Tan over 3 years ago in reply to user3853132

TI__Expert 8420 points

Hi,

It is difficult to find the root cause that make it fail.

But the general reason may cause by Pin voltage out of the max rating value.

0 user3853132 over 3 years ago in reply to Michael Tan

Prodigy 60 points

I get it，thanks.

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TPS2051C: About resistance between OUT pin and GND pin