The AD4116 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.
For AD4116: When the filter is configured to Sinc5+Sinc1 and the fastest output data rate of 62500 SPS is selected.
For a single channel the effective output data rate is 62500 SPS, the time between conversions is 1/ODR = 16us. If “SING_CYC” bit is set or if more than one channel is enabled for the same filter configuration i.e. 62500 SPS then the time between conversions is 80.5us, the delay required is due to the filter settling time.