Nmos trigerring in 4-20mA converter
"Triggered" suggests something that will suddenly switch from one state to another. That's probably not the right word.

As this is an analog circuit we can expect M2 to turn on gradually under certain conditions. "Turned on" would be a better term.

Since the feedback is taken after M2 it means that the output of the op-amp will go as high as it needs to to turn on M2 enough to get the feedback voltage to match the input voltage.







simulate this circuit &ndash; Schematic created using CircuitLab

Figure 1. Running the CircuitLab DC Solver for 4 V in results in 8 V at NODE1.