Op amp rated supply current

Discussion in 'General Electronics Chat' started by gaganaut, May 27, 2010.

  1. gaganaut

    Thread Starter New Member

    May 27, 2010
    Hi all,
    I probably have a very silly question for you all. But being an aerospace engineer, inept in general electronics, makes me ask this question to all the gurus of circuits here.

    So I am working with AD8608 quad op amp (http://bit.ly/brxmO3) for amplifying four signals. The rated voltage for this chip is 5V. In the datasheet one more parameter is given called the "Supply Current per Amplifier" which equals 1mA.

    Now for the power supply I have designed a circuit with 78L05 and 79L05, each of which regulates the voltage to a value of +/-5V at 100mA. So this gives rise to my two questions for you today.

    1. Will the regulators generate a total current of 200mA?
    2. Will this 200mA current, or what have you, be given to the op amp chip, and the supply current rating being less than that, will it get fried?

    I felt that no circuit diagram would be needed to answer these, but please let me know and I can furnish one.

  2. R!f@@

    AAC Fanatic!

    Apr 2, 2009
    The regulator will give you 100mA, not 200mA.
    It's a dual supply, it's like two supplies, each sourcing 100mA

    The OP-AMP will take around a few miliamps. Did you consider the load the amp output see's
    The chip will be fine if you stay with in the Vcc
  3. SgtWookie


    Jul 17, 2007
    Those are single supply opamps, with an operating range of 2.2v to 5.5v. If you try to use them with a dual rail +/-5v supply, you will probably fry them.

    Quiescent current per amplifier is as much as 1.2mA. That goes up when output current increases.

    Better post your circuit, and explain what you are trying to accomplish.