Hi Kelly,
The ADS8900B has an external CONVST pin that controls conversions. The rising edge of CONVST triggers a new conversions, the rising edge brings the device from acquisition state to the conversion phase. You can connect the CONVST pins of multiple ADCs to your controller or FPGA and synchronize multiple ADC's and perform simultaneous conversions.
On the analog side, the ADS8900B incorporates a reference buffer. This allows you to use a single voltage reference such as the REF5050, and connect to the REFIN pin of multiple ADS8900B devices. Each ADS8900B will require is own dedicated REFBUFOUT bypass capacitor as shown in the block diagram below.
Please let me know if you have questions,
Thank you and Kind Regards,
Luis Chioye
Precision ADC Applications
