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.

OPA209: High Speed Amplifier Application Notes

Part Number: OPA209

For Op Amps made of BJT, we are using an resistive circuit for input bias current cancellation. Which kind of method is used to cancel the input bias current for an Op Amp made of CMOS? 

Kindly please answer....

Thanks in advance....

  • Hi Sreehari,

    CMOS OPAmps usually have only very little input bias currents. Then a bias cancelation resistor is not needed.

  • Hai kai klaas69

    Thanks for your response,

    But my question is how to reduce that bias currents further. Is there any method or any trick to make it still less.

    Any kind of suggestions are appreciated.


  • Hi Sreehari,

    the usual input bias current cancelation method does not reduce the input bias currents. It only makes that equal voltage drops are generated at both OPAmp inputs and by this no additional offset voltage is produced. Concretely spoken, two identical offset voltages are generated at each OPAmp input which cancel each other by the operation of OPAmp. Remember, an OPAmp amplifies the voltage difference between the two inputs.