This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

INA190: Output oscillation

Part Number: INA190

Dear All,

I'm using a DCDC regulator to provide a power supply to a class D amplifier. The output DCDC voltage is trimmed by a INA190 curren sensor. It means that if the amplifier needs mor current the INA output will increase and the DCDC voltage will decrease.

The class D amplifier is amplifying a 5MHz clock frequency.

If the 5MHz oscillator is off, the INA's output voltage is a constant DC level as expected.

If the 5MHz oscillator is running, the INA's output voltage is producing an oscillation superposed to the DC voltage around 300/430kHz.

I have tried to filter the INA inputs with a LPF at 10kHz without success.

I can supress this oscillation with a LPF in the INA's output but, due to the oscillation, the output voltage cannot go below 0.8V.

I saw in the datasheet ithat INA is zero drift amplifier that is certainly using a chopper architecture. I suspect the mixer inside the INA to fold RF frequency.

Could you please confirm if my expectation is right?

Could you please propose a way to make the INA immune to RF freq?

Thank you for your help.

Best regards,

Arnaud