INA230: common voltage up to 30V

keisuke

Intellectual 475 points

Part Number: INA230

Is it possible to add some resistor dividers and use the common voltage of the INA230 up to about 30V as follows?

Also, Please tell me about the resistance values that can be used?

thank you.

over 3 years ago

+1 kai klaas69 over 3 years ago

Guru 140200 points

Hi Keisuke,

the effective source resistance of 5k of your scheme (two 10k in parallel) would be much higher than the recommended 10R maximum shown in figure 22 of datasheet.

Another issue is the degrading of common mode rejection. Manfufacturing tolerances of resistors and uneven drift (long-term, temperature) would ruin the input balance of INA230 and heavily degrade the common mode rejection. With 1% toleranced parts only about 40dB common mode rejection could be achieved, with 0.1% toleranced only 60dB. This would be a dramatic worsening compared to the 120dB common mode rejection of naked INA230.

Kai

0 Javier Contreras4 over 3 years ago

TI__Mastermind 28710 points

Hello Keisuke,

I agree with Kai. I would not recommend this at all. We have other power and current monitors that are able to go above 30V that are options for you.

https://www.ti.com/amplifier-circuit/current-sense/power-current-monitors/products.html#p726max=30;85

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INA230: common voltage up to 30V