AD1974 Daisy Chain

Question

Hi, 
 1) Regarding the AD1974, the data sheet mentions that 16 channels are supported. However, the example of daisy chaining the AD1974 only shows two addition devices - is it in fact possible to connect 4 x AD1974 together? 
 2) If 4 devices are supported, how are they connected, are there any example schematics etc? 
 3) Can a single 12.288mhz oscillator drive all the clocks directly and support 48khz sampling rate for all 12-16 channels? 
 4) Finally, the data sheet shows the connection with a Sharc with ABCLK going to both TxCLK and RxCLK. Why is does it need to go to TxCLK? 
 Thanks

ColemanR · Accepted Answer

Hi, 
 I have attached a diagram that shows the hookup for 4 x AD1974 in Daisy Chain mode. Please note that you must use 24.576 MHz in order to get the clock rates high enough to support 16 channels (BCLK will be 24.576 MHz in this design). In the attached schematic, ADC1 is the BCLK and LRCLK Master and all of the devices are driven from a single 24.576 MHz source. The only reason that the ABCLK would be routed to the TxCLK would be to have all of the ports in the SHARC synchronous; there is nothing about the AD1974 that would require this. 
 Regards, 
 Coleman)

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AD1974 Daisy Chain