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OPA2188: How to check the opamp's datasheet for ensure that the opamp is unity-gain stable?

Part Number: OPA2188

Hi team:

How to check the opamp's datasheet for ensure that the opamp is unity-gain stable?

Is OPA2188 unity-gain stable?

Is OPA2188 can be use for voltage follower?

  • Well Alan, 

    Normally the data sheet says that on the front page - this one seems to be silent on unity gain stability, but the Aol and closed loop gain of 1 curves says it is unity gain stable, I was looking at the single version here - usually the original and the same as the dual. 

    Here is the plots - I always find that Cl = 100pF (here, different in other parts) a bit odd - do you need to add it to get stability, or is this saying it will handle that much? But the Aol curve crosses 0dB with plenty of phase margin and the closed loop gain of 1 shows little peaking indicating stability, 

  • Hi Allan,

    Thanks for Michael's reply. 

    If your unity gain buffer is driving C_L < 100pF, then the circuit should be stable as explained by Michael.

    I checked with the simulation, where unity gain BW is approx. 2.36MHz, phase margin is approx. 73.1 degree with R_L= 10kOhm, C_L= 0  pf. 

    If you have other questions, please let us know.

    Best,

    Raymond