I am replacing a 2N2222 BJT inverter circuit with a MOSFET. The circuit needs to feed into the CW and CCW direction pins on a motor driver board, setting one high and then the other at 8-10kHz. So the switching needs to be clean and not introduce much of a delay in inverted half of the waveform that completes the cycle. But I worry the wrong MOSFET with a high RDS will do the same thing as the transistor with its .7V drop and switching delay.
The input signal is a digital pulse train and I would like clean 50us and 100us pulses where the one part of the pulse goes to the non-inverted input and then hopefully an equal pulse goes to the other completing each cycle. The input is a 5V signal from a microcontroller and the output is logic level into another high impedance circuit in the motor driver. Not being familiar with the popular and cheap MOSFETS, I looked at the 2N7000 and BS170, FQP30N06L, I wondered about switching time and anything else I need to think about for a good design. Do I need a GS resistor? Here is my sample circuit. In the simulator, I made the voltage 2.5V with a 2.5V DC offset to get a 0-5V pulse:
And the modeled waveform looks like this. Orange is the input pulse and blue is the inverted pulse. The switching time seems to be just 1 or 2 microseconds, but there it a small clipped off corner in the rising edge of the inverted pulse. What might cause that?: