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AD8129 single supply range

Question asked by steechungca on Sep 16, 2015
Latest reply on Sep 23, 2015 by harryh

Greetings,

 

I want to use the AD8129 as a high frequency high side current sensor in my switched mode power supply. The AD8129 would measure voltage across a shunt resistor on the high side of the SMPS output voltage, so the common mode voltage would be 13V. I want to power the AD8129 with a single +15V supply, where -Vs is 0, and use resistor dividers to offset the amplifier output voltage to ~1.5V via the REF pin. The output of the amplifier goes to a comparator that is on a +3.3V supply. Is this possible?

 

I have begun testing this circuit, but the output voltage seems to be offset at ~4V given resistor values that I calculated from the datasheet.

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