AD9650 SPI


As AD9650 can be configured through SPI so we just need to connect only SCLK, SDIO, CSB with the port. All other pins likeSYNC, OEB, PDWN, DCO, OR  should be left floating then ? or they have to be connected to the ground? 

Thank You

Best Regards


  • 0
    •  Analog Employees 
    on Mar 11, 2019 5:10 PM

    Hi Uzair,

    Yes, if the AD9650 is only planned to be operated in SPI mode the SYNC, OEB, PDWN, DCO, OR pins can be left floating. The OEB, PDWN pins have weak 26K internal pulldowns as shown in d/s figs 72 & 76. Some customers choose to tie OEB, PDWN pins to GND to ensure they can never inadvertently be pulled high as that would effectively disable the ADC outputs. DCO, OR are digital outputs so they should always be left floating if unused. DCO would typically be connected to the Receiver Logic and used to latch the ADC outputs into the FPGA/ASIC. Are you sure you won't be using DCO ?

    Best Regards,