This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

OPA2694 huge power consumption

Other Parts Discussed in Thread: OPA2694


In ma design OPA2694 is drawing around 90mA per chip from each of +/-5V rail. When I change the feedback resistors to higher than 10k current consumption drops to nominal 10mA. I have the same situation on five boards, with two channels on each one - total of 20chips. The design worked perfectly on different amplifiers.

I would appreciate any suggestions how to solve the problem.

  • We will need some more information to help you debug this.  Can you attach a schematic?

    With CF op amps using a larger feedback resistor lowers the loop gain and makes the device more stable.  This could indicate that the amplifier is oscillating in the previous configuration.  There is also a possiblity that the input common mode or gain setting is causing the output to saturate and the larger resistor somehow offsets this problem. 

    For this amplifier 10k sounds too large.  There should be a better way to fix the problem. 

    An easy step for debugging is to take DC measurements of all of the pin voltages and compare them to the datasheet ranges.  I would recommend doing this for the 90mA condition and the 10mA condition with the 10k resistor.  If you can list these DC voltages along with your schematic it would help do debug your circuit.