INA826: About the RG pin on the INA826

Sato Kiyohiko

Prodigy 10 points

Part Number: INA826
Other Parts Discussed in Thread: TINA-TI

Can the INA826 RG 2-pin and RG 3-pin be used in the OPEN configuration?

4 months ago

0 Robert Clifton56 4 months ago

TI__Mastermind 30980 points

Hello Kiyohiko-san,

You can keep the RG pins (2 and 3) open on the INA826. Doing so will produce a gain of 1V/V.

Let me know if you have any other questions.

Best Regards,

Robert Clifton

0 Sato Kiyohiko 4 months ago in reply to Robert Clifton56

Prodigy 10 points

Hello, Mr. Robert Clifton.

Thank you for your response.
I understand your answer.

I have an additional question.
・If pins 2 and 3 are open, I am concerned that noise will appear on the output pin if noise enters pins 2 and 3.

Therefore, with the goal of bringing the gain closer to 1V/V, I am considering adding a 1MΩ pull-down resistor between “pins 2,3” - GND”.

Is this approach correct?
I performed a simple DC analysis of the circuit using TINA-TI.
The result was almost exactly “gain = 1 V/V.”

Best Regards,
Sato Kiyohiko

0 Robert Clifton56 4 months ago in reply to Sato Kiyohiko

TI__Mastermind 30980 points

Hello Kiyohiko-san,

My concern would be resistor mismatch, would cause the inputs to be imbalanced.

I also don't think that this would be necessary. Pins 2 and 3 are low impedance as it's going through the feedback resistors as shown in the schematic below:

Best Regards,

Robert Clifton

0 Sato Kiyohiko 4 months ago in reply to Robert Clifton56

Prodigy 10 points

Hello, Mr. Robert Clifton.

Thank you for your response.
I understand your answer.

Best Regards,
Sato Kiyohiko

0 Robert Clifton56 4 months ago in reply to Sato Kiyohiko

TI__Mastermind 30980 points

Hello Kiyohiko-san,

Let us know if you have any further question.

Best Regards,

Robert Clifton

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INA826: About the RG pin on the INA826