VCC = 3.3V, the input signal of pin 6 of the op amp is a 1KHz sine wave whose midpoint is VCC/2, and the PP value does not exceed VCC or below GND.
The output of pin 7 of the op amp is a 1KHz square wave, but the ratio of high to low in one cycle is not 50:50, but 40:60.
The most problematic is that the 5 pin of the op amp is also a 1KHz square wave, but the high level is .5V and the low level is 1.05V.
But according to the picture, the high level of pin 5 should be 1.81V, and the low level should be 1.48V.
Very strange, please help analyze it.
The op amp is not a comparator, but an operational amplifier.
Thank you!
Amari Posted on August 5, 2020
Is it basically normal? It's similar to Schmitt trigger. I don't see any problems.
If you want to output a sine wave, you must connect it to negative feedback.
Justice Posted on August 5, 2020
It is estimated that the landlord uses a single power supply
See how high and low the output of pin 7 is?
If it is not a rail-to-rail op amp, the output square wave is probably not 1:1
Ollie Posted on August 5, 2020
The effect of increasing the capacitance is to slow down the feedback response to the output.
