INA240-Q1: Out put voltage calculation

DARSHAN M M V

Intellectual 265 points

Part Number: INA240-Q1

Tool/software:

Hello team,

I am using INA240A1-Q1 in my design to sense the 10A current , Please validate my calculation below

Vout= Iload*Rsense*Gain

=10A*15mohm*20

=3V

If my load current is 10A through sense resistor,Opamp output will be 3V 20V/V gain - is my assumption is correct ?

2 months ago

0 DARSHAN M M V 2 months ago

Intellectual 265 points

for the above question , do I need to add off set Volatge to the output equation

=Vos*Acl+Vout

0 Louis L 2 months ago in reply to DARSHAN M M V

TI__Expert 4580 points

Darshan,

Thank you for your patience. Due to the U.S. holiday, the team is out of the office, but will reply when we return on Tuesday, 1/21.

Louis

0 Guang Zhou 2 months ago in reply to Louis L

TI__Mastermind 31840 points

Hi Darshan,

Your calculation is correct, ie, with 15mohm and gain of 20, a 10A current yields a 3V nominal output. Considering the effect of offset (which can be positive or negative), simply add or subtract Vos*20 to 3V.

If you plan to connect REF pins to an voltage other than ground, simply add the REF voltage to the output as well.

Regards

Guang

0 DARSHAN M M V 1 month ago in reply to Guang Zhou

Intellectual 265 points

Hello Guang,

What exactly means the common mode voltage in opamp ,it is really confusing me to Understand practically.what is the advantage of having higher common mode voltage.
what is the common mode rejection ration?do we have an advantage with higher dB of CMRR
and also please help me understand PSRR and its value to be considered- should be high or low for a stable operation?

0 Guang Zhou 1 month ago in reply to DARSHAN M M V

TI__Mastermind 31840 points

Hi Darshan,

I’d like to direct you to our video series with the exact topics you’re interested in. These presentations do a much better job than I can explain with a short post. Please view these topics, and take the quizzes afterwards.

Regards

Guang

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INA240-Q1: Out put voltage calculation