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ADA4610-1 huge supply current

Question asked by cseppento on Nov 14, 2017
Latest reply on Nov 16, 2017 by krisf

Hi Everyone,

 

I am using an ADA4610-1 opamp in an active loop filter for a PLL. However, after soldering it on my PCB, with the PLL turned off (no supply voltage, so no current on the charge pump output either) and giving 25V single supply voltage to the opamp, the input current is not a few mA as in the datasheet but 70mA (!!!). It increases with increasing supply voltage. What could cause this? Similar problems arised using another amplifier on another PCB. That time the opamp got really hot, now I disconnected the voltage immediately as soon as I saw the current measurement on the supply, because I wouldn't like to blow it up.

I have triple-checked my board and the soldering of the pins, there are no shorts.

I enclosed the relevant part of my schematic.

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