I'm controlling a home-built current regulator, using a PIC microcontroller (PIC12F1572).
The regulator is implemented using an op-amp and mosfet, and works well. The input to the regulator is a voltage 0V to 0.25V, with zero corresponding to 0A and 0.25V corresponding to 0.5A.
I'm thinking of controlling the current regulator directly from the PIC, by having a resistor based voltage divider connected to an output pin on the PIC, to yield between ~0V and 0.25V.
According to the datasheet for the PIC, the output low is guaranteed to be at most 0.6V. With my voltage divider, this means ~0.03V to the current regulator, or approx 60mA out.
However, I want it to be able to shut off completely.
The output low quoted in the datasheet is valid at 8mA, so when (practically) unloaded, it should give lower voltage.
Do I dare assume that the output low voltage will always be very close to zero in practice under these conditions? Or am I inviting trouble?