ADS5407 Syncronization

Hi.

Multiple ADS5407 can be synchronized, up to your ability to control the clocking and SYNC inputs to be synchronized up to all the ADCs in the system.

The ADS5407 has a 5 bit counter that can output a divide-by-32 signal on the SYNC output, and the SYNC output can be initialized by the SYNC input.  So if you can deliver the sample clock to any arbitrary number of data converters all synchronized, *and* deliver a SYNC input to all these data converters such that setup/hold time is satisfied around the same clock edge for all the data converters, then the SYNC output from all the data converters can be synchronized.  There may be differences in prop delay from sample clock to output data for each of the data converters, but the SYNC output from each converter could be used to identify which samples across all the multiple converters all came from the same sample clock edge.  The SYNC output can be latched with the sample data as if it were an extra data bit and then the SYNC output pattern can be used to 'line up' the samples from all the data converters.

The SYNC input could be a single pulse to all the data converters at the same time to make all the data converters start their 32-state counters at the same time, or the SYNC input could be a divided-down version of the sample clock, such as sampleclock/32 or sampleclock/64 and so forth.   Once a rising edge of SYNC starts off the counters, the counters will just wrap around and repeat with a period of 32 if there are no more rising edges of the SYNC input.  But if the SYNC input is periodic then the rising edges of the SYNC input should be on  spacing of multiples of 32 so as to not disturb the position of the counters and cause them to jump count.

Regards,

Richard P.