If you are using a dsPIC33 device with 2 AD modules, you then have a lot of flexibility concerning how you allocate your AD module resources. If you select both AD modules as 10-bit, you will have 8 total sample and hold channels, capable of taking 8 simultaneous samples. The total conversion throughput of this system would be 2.2 mega samples per second. Another option is to configure both AD modules as 12-bit converters. Here, you will have 2 sample and hold channels, capable of taking 2 simultaneous samples and having a total conversion throughput of 1 mega samples per second. Another option is the configure one module as 10-bit and one module as 12-bit. This can provide flexibility of having high speed lower resolution conversions at the same time as lower speed higher resolution conversions.