I encountered a problem that require a constant turn over threshold voltage of an inverter over a supply voltage range of 5V ~ 2.5V, and the voltage is better to be 1.1V. For example, at vdd=2.5V, the voltage is 1.1V, and at vdd=5V, the voltage is about 1.2-1.3V.
Seems that it is difficult to achieve this goal. Could anyone give some advice?
theoratically, a CMOS process variation will prevent a simple inverter from having a constant trip point, so one of the easy way is to use a bandgap to generate a reference voltage and an inverter to compare your input signal against that reference voltage for a digital output, not sure if it fits for your circuit.
Re: How to get a constant turn over theshold voltage of inve
Implement your inverter with a differential pair whose non-inverting input is tied to a reference of about 1.1 (your threshold) and the input signal sweeps the inverting input.
It's not possible to make constant trip point for inverter. If in ur process VthN~0.9V u can try to make nmos much more stronger than pmos so trip point will be close to ~1V for ur supply range.