INA190: High-side current source

Bryan McLaughlin

Part Number: INA190
Other Parts Discussed in Thread: OPA187

Tool/software:

I need to create a high-side DC current source which will be adjustable from 100-1000uA. The supply rail is 5V.

The plan is to use a Precision DAC for setting the reference (IN+) of a Precision Op-Amp, and closing the loop (IN-) with a shunt resistor and INA190:

Rshunt = 100R

INA190 G=25

VDAC = 0.025-2.5V --> 100-1000uA

Amp is probably OPA187

Do you have any guidance on this application?

Thanks

over 1 year ago

0 Mallika Senthil over 1 year ago

TI__Genius 9090 points

Hi Bryan,

The following is a reference circuit tool you could use,
https://www.ti.com/tool/CIRCUIT060043

Best,
Mallika Senthil

0 Bryan McLaughlin over 1 year ago in reply to Mallika Senthil

Expert 1110 points

Thanks, Mallika. I ran the sim from SLAU507 replacing with INA190 and am getting the results I want.

In another post about a similar circuit they mentioned: "As for the op amp, you would want one with a unity gain bandwidth that is similar or greater than the closed-loop BW of the current sense amplifier."

Does this advice apply with INA190? Acl=25V/V for the INA190A1?

Thanks

+1 Mallika Senthil over 1 year ago in reply to Bryan McLaughlin

TI__Genius 9090 points

Hi Bryan,

Yes, that would apply to the INA190 in your use case as well.
For more information please follow the link below.
https://www.ti.com/video/4080307150001

Best,
Mallika Senthil

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INA190: High-side current source