I have to provide an isolated voltage that spans between 0V and 3V. Accuracy and space are more important than cost.
The only solution I see (without go to digital) is to use something like ISO122/124. The drawbacks are:
- they require a dual supply, so I need two DCDCs to provide rails for both sides
- space: the package is quite big and also the two DCDCs are bulky
I've already two isolated 5V voltage on both sides, and I would like to use them.
I found many cheap isolation amplifier but with only few hundreds mV of input range (they are for shunt resistor). Another way is to scale down and then up my signal to fit these constraints but I'm afraid about the accuracy when I'm close to 0V.
EDIT
I add some more information about my scenario:
- the signal is pretty close to DC, say 1 Hz bandwidth
- on the second side there is a 16-bit ADC, the accuracy needed is about 1-2 LSB