INA188: Recommend RC value

Shuhei Goto

Part Number: INA188
Other Parts Discussed in Thread: OPA188,

Hi team,

In datasheet 7.3.3.3, it is said that low-pass filter is recommended to avoid transient noise for zero-drift amp.
In this case, what value of RC are recommended?

Best regards,

Goto

5 months ago

0 Raymond Zhang1 5 months ago

TI__Guru 54111 points

Hi Goto-san,

Shuhei Goto said:
In this case, what value of RC are recommended?

Please follow the recommended R value as shown below, see the application note.

https://www.ti.com/lit/wp/sboa586/sboa586.pdf?ts=1713775401290&ref_url=https%253A%252F%252Fwww.google.com%252F

The C value in the filter depends on the actual application, which it limits the BW of OPA188 op amp per your design requirements. The dominated pole in the OPA188 may be set wherever that will be suitable for the design.

If you have additional questions, please let us know.

Best,

Raymond

0 Shuhei Goto 5 months ago in reply to Raymond Zhang1

TI__Intellectual 2250 points

Hi Raymond,

Thank you for reply.

Also, Where should I use a low-pass filter for the INA188?

Many thanks,
Goto

+1 Raymond Zhang1 5 months ago in reply to Shuhei Goto

TI__Guru 54111 points

Hi Goto-san,

Shuhei Goto said:
Where should I use a low-pass filter for the INA188?

To limit the BW of an op amp, you may use technique similar to the image below. This is non-inverting input configuration.

The following technique is recommended for chopper amplifier. The above configuration will work as well, but our lab data is shown that this LPF configuration is better suited for the chopper amplifiers.

If you have other questions, please let me know.

Best,

Raymond

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INA188: Recommend RC value