Q11. What is the difference in output data rate between multiple channel configuration and single channel configurations for AD4111/AD4112/AD4114/AD4115?
The AD4111/AD4112/AD4114/AD4115 can run at faster output data rates when converting on a single channel. When multiple channels are enabled the digital filter must settle fully for each channel and therefore the result is a slower output data rate.
As an example, For AD4111/AD4112/AD4114: When the filter is configured to Sinc5+Sinc1 and the fastest output data rate of 31250 SPS is selected.
For a single channel the effective output data rate is 31250 SPS, the time between conversions is 1/ODR = 32us. If “SING_CYC” bit is set or If more than one channel is enabled for the same filter configuration i.e. 31250 SPS then the time between conversions is 161us, because the digital filter must fully settle for each output. For more details about the timing you can download and view the AD4111 Filter Model.
For AD4115: When the filter is configured to Sinc5+Sinc1 and the fastest output data rate of 125000 SPS is selected.
For a single channel the effective output data rate is 125000 SPS, the time between conversions is 1/ODR = 8us. If “SING_CYC” bit is set or If more than one channel is enabled for the same filter configuration i.e. 125000 SPS then the time between conversions is 40.25us, the delay required is due to the filter settling time. For more details about the timing you can download and view the AD4115 Filter Model.