Precision Measurement with Optical Comparators

This simulation compares an op-amp used as a linear amplifier versus used as a comparator. The violet trace at the top is the 1 kHz input sine; the green trace shows the amplifier output which follows the input smoothly with gain and remains within the op-amp’s linear region thanks to negative feedback — you can see a larger amplitude sinusoid with low distortion and Vpp ≈ 10V. The red trace is the comparator output: instead of a scaled sine it snaps between ±supply rails, producing a clean squa