差动输入钳位—它们影响您的运算放大器电路吗?
Differential Input Clamps--can they affect your op amp circuits?
Bruce Trump
Last week we looked at the effect that internal differential input clamp
diodes could have on op amps when used as a comparator. I posed a question--
can these clamps affect op amp circuits. Op amps should have near zero
volts between the two input terminals, right? So these diodes will never
forward bias in normal op amp circuits... or will they?
Just a reminder, we’re talking about the differential clamp diodes that may
be present in some op amps, see figure 1.
[pic]
The effect in op amp circuits is often seen in the basic non-inverting
amplifier configurations, including a simple G=1 buffer amplifier. Consider
a positive-going input step. The output cannot immediately follow the
a……