As we can see here, we need the following power supplies:
- 4 × 5V for AVDD
- 2 × 5V for VBIAS
- 2 × 3.3V for DVDD
We could provide all this with just 2 regulators, but I am very tempted to use 8 instead. If we do, we would use this earlier design. Then, we would have to decide how to integrate these 8 regulators. We pretty much have three options:
- Directly on the ADC SO-DIMM module.
- As separate boards mounted on the ADC SO-DIMM module.
- As separate boards mounted on the backplane.
I will seek the advice of an expert for this relatively tricky question, but I am suspecting that we will end up going for the third option, for the following reasons:
- The SO-DIMM module is likely to be too small for 8 boards.
- This would decouple the ADC module’s design from its regulators.
- This would make it easier to test different configurations.