AD8629 input square wave abnormality

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AD8629 input square wave abnormality [Copy link]

AD8629 and FZT1047A are used to form a V/I conversion circuit. The input is a square wave voltage UH=3V, UL=0.45V, f=20kHz. The output is a square wave current IH=200mA, IL=30mA, f=20kHz. The PSpice simulation circuit is as follows. The simulation found that there is overshoot and oscillation at the op amp's in-phase input. The op amp is connected as a follower, and the same happens. Why is this? How to eliminate it?

qwqwqw2088

Poor power supply decoupling or feedback network of the op amp may cause them to be unstable, resulting in overshoot and oscillation.

If the op amp is connected as a follower, and the same is true, you can consider that the simulation model is wrong.

MHMT

If it does oscillate, try increasing the resistance or removing some capacitors.