I have a question regarding Schmitt Trigger. I am trying to design an inverting output (at UTP=Low, at LTP=High) Schmitt Trigger for an application. However, I need to use PNP transistors since the voltage level is relatively high (60V) for opamp application. Unfortunately, on the internet only non-inverting transistor Schmitt trigger is available. Therefore could anyone tell me how I can implement an inverting Schmitt trigger with PNP transistors?