Tying program select and unused pot pins to ground
Moderator: frank
Tying program select and unused pot pins to ground
I know this probably sounds like a daft question but if the program select and pot inputs are not switched or controlled in any way (ie an application that only uses one program and has not controls), can these pins be tied directly to ground or is there any reason to include a resistor? I've seen some circuits about with resistors in there and I wasn't sure whether they were just vestigial remnants of cannibalised circuits or whether I'd missed some facet of the chip architecture that requires them...
Re: Tying program select and unused pot pins to ground
Pots can be leaved floating if the code does not read them. S0/S1/S2 has to go to GND or 3v3 to select the program properly, no resistor needed. When I design a PCB and some of those pins are not needed I tied them to ground or 3v3 according to the PCB needs.
Re: Tying program select and unused pot pins to ground
Great thanks for your reply. So there's no danger of noise affecting other aspects of the chip if the pot pins are left floating?