Voltage to Current (V-I) Converter

The circuit shown here is a high-side voltage-to-current (V-I) converter. It translates an input voltage of 0 V to 2 V to an output current of 0 mA to 100 mA. The low offset voltage and offset drift of the OPA2333 facilitate excellent DC accuracy for the circuit.

The project provides a high-side current source that supplies an adjustable current to a ground reference load. The first op-amp stage sets a reference current based on the input control voltage. The second op-amp stage acts as a current mirror that gains the reference current and regulates the current sourced from the output PMOSFET Q2 to the load. R2, R4, and R10 set the output current based on the input control voltage. Components C7, R9, R8, R7, C6, R3 provide compensation to ensure stability of the circuit.