INA190: Output ringing issue

ttd

Part Number: INA190

Dear Technical Support Team,

I have questions about INA190A2.

(question 1)
A ringing waveform has been confirmed for about 1.5 mS from the saturation of the output voltage to the stability.
Would you please tell me if there is a way to shorten it or eliminate ringing?

When the current flowing through the resistor 40Ω changes from 5mA to 0mA
A ringing waveform is observed at the output voltage.

(Question 2)
Even when the ENABLE signal is switched from OFF to ON, the ringing waveform is between about 150uS.
It will happen. Please let me know if you have any countermeasures for this as well.

■Configuration

Shunt resister 40Ω

REF is driven by 2V buffer AMP.

VS= 5V

Best Regards,

ttd

over 5 years ago

0 kai klaas69 over 5 years ago

Guru 140200 points

Hi,

what is connected to the output of INA190? Please show a schematic :-)

Kai

0 Carolus Andrews over 5 years ago

TI__Mastermind 26165 points

ttd,

Thanks for choosing the forums. I'm in agreeance with Kai, could we begin by examining your schematic here? Please make sure that when you post it, you use the insert file on the taskbar. Copy/Paste is not supported in the forum.

0 ttd over 5 years ago in reply to Carolus Andrews

Mastermind 9365 points

Hi,

Sorry for my reply.

See attached pdf.

INA190.pdf

Best Regards,

ttd

0 Carolus Andrews over 5 years ago in reply to ttd

TI__Mastermind 26165 points

TTD,

I've reached out to our design team to see if they have any input on this. I'll follow up by end of day tomorrow, hopefully with some answers.

0 Carolus Andrews over 5 years ago in reply to Carolus Andrews

TI__Mastermind 26165 points

ttd,

I've had a chance to look at this. This behavior is actually inherent to the INA190 leaving saturation from the VS rail, and your circuit is fine. The ringing is an artefact of the internal switching capacitor structure internal to the INA190. As it is the device recovering from non-linear behavior, there really isn't much I can recommend to improve the time of the response. I would advise maintaining linear operation with the device and not saturating against the rails.

The ringing you see is inherent to the switching capacitors internal to the device. The frequency seen here looks like it is close to 100kHz, so an input or output filter may help reduce the magnitude of this response.

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INA190: Output ringing issue