JAJSHR5A January 2015 – August 2019 ADS54J54
PRODUCTION DATA.
The ADS54J54 provides several different options to interface it to the digital processor or processors. If the ADS54J54 device is operated in split sampling rate (2 channels at 500-MSPS output rate and 2 channels at 250-MSPS output rate), then it requires dual SYSREF (SYSREFAB and SYSREFCD) and dual SYNC (SYNCbAB and SYNCbCD).
Subclass 1 – Deterministic Latency: The device clock and synchronous SYSREF signal are provided by the timing unit to the ADS54J54 and the processor. The processor controls the SYNCb input signals for the JESD204B state machine for all four channels. In case the ADS54J54 is connected to two different processors, the differential SYNCb inputs of the ADS54J54 can be configured to two single-ended inputs where each pin controls the JESD204B state machine of the two corresponding channels.
Split Mode Operation: If the ADS54J54 device is operated with 2-channel output at 500 MSPS and 2-channel output at 250 MSPS, then dual SYSREF (SYSREFAB for channel A and B, SYSREFCD for channel C and D) as well as dual SYNC (SYNCbAB for channel A and B, SYNCbCD for channel C and D) is required to ensure normal operation because the JESD204B link configuration is different for the two channel pairs.