When changing channel selections, the user
should observe the following guidelines to ensure that the correct channel is selected:
- In Single Conversion mode, always
select the channel before starting the conversion. The channel selection may be
changed one ADC clock cycle after writing one to ADSC. However, the simplest method
is to wait for the conversion to complete before changing the channel selection.
- In Free Running mode, always select
the channel before starting the first conversion. The channel selection may be
changed one ADC clock cycle after writing one to ADSC. However, the simplest method
is to wait for the first conversion to complete, and then change the channel
selection. Since the next conversion has already started automatically, the next
result will reflect the previous channel selection. Subsequent conversions will
reflect the new channel selection.
The user is advised not to write new channel or reference selection values during Free
Running mode.
When switching to a differential gain
channel, the first conversion result may have a poor accuracy due to the required settling
time for the automatic offset cancellation circuitry. The user should preferably disregard
the first conversion result.