INA381: Error analysis for > 100mOhm sense resistor

Barrett Bryan

Part Number: INA381

In the design tool for error analysis on ti.com, the ideal shunt resistor is capped at 100mOhm. What error would be expected when using a 1Ohm resistor for 200mA max current?

over 6 years ago

0 Patrick Simmons over 6 years ago

TI__Mastermind 26335 points

Hello Barrett,

Thanks for using our forum. It is a holiday for TI employees in the United States today. Our next business day is on Monday (11/26), starting at 8 a.m. mountain standard time. We will get back to you with a response to your issue on that day.

0 Patrick Simmons over 6 years ago in reply to Patrick Simmons

TI__Mastermind 26335 points

Hello Barrett,

Sorry about the delay. I had to get access to the tool. Below is the curve I generated for your conditions. This is for the INA381A1. Let me know if you want to see the error curves for one the other variants.

0 Barrett Bryan over 6 years ago in reply to Patrick Simmons

TI__Intellectual 1010 points

Hi Patrick,

Do you mind checking data for the following operating conditions:

• temp range is from -20°C to 85°C
• sensing resistor tolerance is 1%
• common voltage is 8V and 3.6V
• supply voltage is 3.3V

Thanks!

0 Patrick Simmons over 6 years ago in reply to Barrett Bryan

TI__Mastermind 26335 points

Hello Barrett,

The worst case curve for your ranges, was observed under the following conditions:

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INA381: Error analysis for > 100mOhm sense resistor