I am already using the AD627 that I find fantastic for example strain gauge measurement.

Now, my problem is to measure a current through a shunt of max 70 mV.

It is a PWM signal, thus, the information is a pulse where frequency is stable but the modulation is not. 

Therefore my output is also a pulse, what I can not use because I need a DC information, not a PWM one.

So, is there a special schematic / add/ filtering / else that I have forgotten ? 

In summary, I have a shunt before the load that works in PWM mode. I want to measure the current and get a DC voltage. Possible  with the AD 627 ?

Thanks for your help



IN+ voltage versus GroundIN+ : IN- differential voltage on shunt

Parents Reply
  • Hello

    I have succeeded to make it working with a RC filter after the output of the AD627. This one is a real exceptional amplifier. Thanks to everybody for the idea about the RC.

    Now, my friend, make me a favor and tell me if you know a AD627 that could have an input in a range of 0-30V. I work on a automotive application and as you know, alternators could go up to 28V-30V depending on the truck.

    AD627 is for a current sens PWM 1KHz measuring 100A - 35 mV.

    So, any idea for a "AD627" like for a voltage inputs in a range of 28V-30V ? I tried to find it on the website, nada..

     I have tried to put the sense shunt down, but at 35 mV, it is a soup, noisy and the RC is not effective at all. 

    Regards and merci beaucoup !!