MCP3208 Differential Mode

DigitalBob

I was wondering if anyone has used this IC in diff mode. I used Mode=0 in the Con but the readings look unequal. CH0+, CH1- 5volts reads solid 5 volts. CH0-, CH1+ reads 4.8 volts looks a little weak in one polarity.

Peter Jakacki

I'm hooking up a couple of 3208s at the moment so I will report back but bear in mind that this is only pseudo-differential so each voltage must still be within range of the A/D chip itself. If you want true differential then you need an opamp. I've got two of these babies connected in biased resistor networks to read 240V 3-phase with a Prop on it's own isolated board.

DigitalBob

Thanks and your project looks nicely done. I also like the 16 bit MCP3426 it reads diff and has built in PGA .