I need to measure the current through a resistor. Any suggestions for a current sense amplifier?

Thread Starter

chamal1996

Joined Oct 7, 2020
11
Please find the figure in below. I need to get feedback of current which is flowing through the R10.

Maximum current:- 25 mA (Bi-directional)
Input Common mode voltage can be :- -/+ 25.5 V

There are some current sense amplifiers in Texas Instruments. But the issue is those sensors minimum ratings for the common-mode voltage is -22 V.
I've also attached the datasheet of one current sensor.

Is there any way to overcome this challenge or Is there any component which suits my application?
 

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andrewmm

Joined Feb 25, 2011
907
would this work ?
https://www.analog.com/en/products/ltc2946.html#product-overview

or this

https://www.analog.com/en/products/ltc2944.html

Idea would be to float the chips at the supply voltage , be that 2Kv or whatever,
then use an isolated i2C / SMB bus driver to connect it to your uProc.

such as

https://www.analog.com/en/products/ltm2886.html

You could even use the Power option in the above isolator to power the circuit, as its floating also.

Can I have a bit more details,
like, how fast is the current changing
I see the letters 2Kv on the snippet you show, is this the voltage above ground ?
whats the+- 25 volts come into effect, is this +- 25 v off of 2Kv ?
 
Last edited:

Thread Starter

chamal1996

Joined Oct 7, 2020
11
would this work ?
https://www.analog.com/en/products/ltc2946.html#product-overview

or this

https://www.analog.com/en/products/ltc2944.html

Idea would be to float the chips at the supply voltage , be that 2Kv or whatever,
then use an isolated i2C / SMB bus driver to connect it to your uProc.

such as

https://www.analog.com/en/products/ltm2886.html

You could even use the Power option in the above isolator to power the circuit, as its floating also.

Can I have a bit more details,
like, how fast is the current changing
I see the letters 2Kv on the snippet you show, is this the voltage above ground ?
whats the+- 25 volts come into effect, is this +- 25 v off of 2Kv ?
Actually, I'm designing an electrical stimulator. For that, to set the safety margin according to user input I need current feedback through the output electrodes. For 180us electrode voltage should be able to rise 25V(positive terminal) and -25V (negative terminal). For next 180us voltages will be switched. After that, next 24ms voltage between electrode is zero
 
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