ADS131M08: About Global-chop and SYNC

Hi ?? ?,

Here are the answers to your questions

yifei Zhang said:

n global-chop mode, does the ADC wait for the Global-chop delay after a sample is completed before it automatically starts another sample? And in “Sampling N”, Is N a sampling period or a sampling point?

Yes, the ADC waits for the delay after a sample is completed before starting the next sample. This is to allow time for the inputs to settle after swapping them

Sampling N is a conversion period, which is the time during which the delta-sigma modulator samples the analog input, filters the data, and decimates the output. Actual output data is available when it says "1st global chop conversion result" and "2nd global chop conversion result" in the diagram.

yifei Zhang said:

f Global-chop delay [GC_DLY] is set to a long enough time, for example, a maximum of 65536 tMOD, GC_DLY can delay a maximum of 0.016 seconds if the tMOD is 1/4.096M second. If a trigger signal is generated on the SYNC pin at 6400 Hz, its period is 0.00015625 seconds, much less than GC_DLY's 0.016 seconds. So whether the ADS131M08 can be sampled according to 6400 Hz of the trigger signal.

Yes, you should not trigger a sync in less time than the GC delay. But I am also not sure why you would do this

-Bryan