measuring current using instrumentation amplifier

[gehan_s]

hey all, this is my first post in this forum.

i want to measure load current using a instrumentation amplifier (for a power supply). i was planing to put a 1 ohm resistor in series with the load and measure the voltage difference using the in-amp (AD623) but the voltages at the 2 input pins exceed 20V which i think is not good for it. how can i overcome this and is there a better solution (which should be low cost) ?????

thanks in advance

 

[Genovator]

What is your measuring voltage????
This one has input limit of 48v. http://cds.linear.com/docs/Datasheet/6100fb.pdf

 

[gehan_s]

thank you verymuch for the reply

the maximum DIFFERENCE voltage will be 1V (since my maximum load current will be 1A) but the maximum O/P voltage will be about 40V. for an example when the load is drawing 500mA at 35V, the in-amp's + and - pins will be at 35.5V and 35V

 

[Avla 0652]

These are lots of inamps able to handle common-mode voltage much higher than VDD,
for example AD628 can withstand ±120 V at VSupply = ±15 V.

 

[krp]

Is low-side sensing an option?

https://www.ti.com/analog/docs/microsite.tsp?sectionId=560&tabId=2181&micrositeId=7

 

[FvM]

There are "tons" of high side current sense amplifiers available from major manufacturers, with voltage ranges up to 100V or so.