Other Parts Discussed in Thread: LM224, OPA4196
Hi team,
There are some problems in using OPA4188.
The triangle wave generator composed of lm244 in the original design circuit, but it is easily affected by temperature and the signal is unstable. So the zero drift op amp OPA4188 is used instead. This chip and LM244 are the same 4-channel op amp with the same pin and package. but the output waveform and frequency are not correct after replacement.
The original circuit is as follows:
U1B is composed of square wave circuit, U1C is composed of triangle wave circuit, U1A and U1D are composed of comparator. The sampling values of V1 and V2 voltage are compared with the output voltage of triangle wave respectively, and the PWM waveform is output to convert the voltage signal into PWM signal.
In addition:after our analysis, does the 4188 op amp have input clamp, which makes the output incorrect?
Or is there any other low drift op amp suitable for our circuit.
Thanks a lot.