INA240-Q1: Output short fails to ground

Luca Colombo

Part Number: INA240-Q1

Tool/software:

Hello,

I'm currently using INA240-Q1 to retreive the current value from a 500 uOhm shunt resistance. Voltage drop across the shunt resistor is up to 24 V, with peaks of 70 A current. However, besides being in the common mode ranges for the input pins and being the INA240-Q1 powered with a 5 V supply, the device fails and the output shorts to ground.

Any clue on what might be the cause?

Thank you in advance,

Luca

4 months ago

0 Guang Zhou 4 months ago

TI__Mastermind 31760 points

Hi Luca,

Have you checked if the input voltage polarity is not reversed such that the output would be stuck to GND?

Other than that, please measure all pin voltages, and then the differential voltage across IN+ and IN-.

Regards

Guang

0 Luca Colombo 4 months ago in reply to Guang Zhou

Prodigy 10 points

Hi Guang,

thank you for your reply. Voltage polarity is correct, also pin voltages are well within the datasheet tolerance values.

Also, a differential voltage of mV is present at the input of the INA

0 Guang Zhou 4 months ago in reply to Luca Colombo

TI__Mastermind 31760 points

Hi,

Sound like the device is damaged. Please replace it with a fresh unit and see it fixes the problem.

If it does, we should figure out why the damage occurred. One good place to start is to monitor the 5V supply in all operating modes, including power on/off.

Regards

Guang

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INA240-Q1: Output short fails to ground