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50mA sink and source capability Op Amp

Other Parts Discussed in Thread: OPA2172, OPA172, OPA1622, ALM2402-Q1

Hi,

I'm looking for a dual channel Op Amp with 50mA sink and source capability at 70C ambient temperature. Small package size is preferred. The power supply is +3.3V and -3.3V. Output should be rail-to-rail and it almost outputs a DC signal(low bandwidth signal). 

I'm comparing Short-Circuit Current spec. I think OPA2172 in 3X3 QFN would fit.  Could you help confirm it or recommend a better solution?

Thanks.

  • Hi Di,

    As shown in the "Output Voltage vs. Output Current" figure in the OPA172, with +/-50mA at 75C the output will only be able to swing to within 2V - 2.25V of each supply rail.  Therefore with a +/-3.3V supply the maximum output swing is limited between +/-1V and +/-1.3V.  Consider the OPA1622 which can output +/-50mA with output voltages within about 1V from the rails which should increase the usable output swing to greater than +/-2V in your application.

    OPA172 Output swing:

    OPA1622 Output Swing:
      

  • Di Wang,

    ALM2402-Q1 has VOL and VOH specs for 100mA and 200mA.
    It will provide an output that can get quite close to the power rails.