Other Parts Discussed in Thread: EVM430-F6779, , MSP-TS430PEU128, MSP-FET
Hi we are assessing performance of the SD24B using the "EVM430-F6779 - 3 Phase Electronic Watt-Hour EVM for Metering" Demo Board, we set the SD24B to use the following settings:
Fm = 1.8432MHz
OSR = 512
Bits per reading = +/- 2^27 bits.
Vref = 1.25V +/- 1mV (external)
We have modified the 3 voltage channels (CH0:2) and shorted each of the channels together in order to obtain , the unit is powered from a low impedance battery (DVcc = 3V)
The best ENOB that we could achieve using this setup was approximately 16 bits (which after some searching seems consistent with what others have experienced).
However the channel offset is not consistent between reads, it seems to drift +/- 4000 counts is this also to be expected?
I would of expected some variation of offset between channels, but I did not expect the offset to be dynamically changing by such a large amount in a stable environment.
Any help or insight would be greatly appreciated