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AD9959 LPF Filter, SPI 3-wire & I/O Update operation

Question asked by Shahid_DE Employee on May 13, 2015
Latest reply on May 13, 2015 by KennyG



1. I would like to operate AD9959 around 200 MHz-220 MHz. Is an external low pass filter (LPF) "always" needed for this frequency range?


2. The default value of CSR register 0x00 is 0xF0 (Table 28). This set the serial I/O mode in 2-wire mode. Right? 

We use 3-wire as standard and want to keep this. Is there a possibility to set this via HW configuration, or do we always have to reconfigure the “Serial I/O mode select”?


3. Data transfer from SPI input buffer to get active is triggered by “I/O_Update”. Is it possible to trigger this by SW (Register setting) or do we have to spend an additional signal line to serve this signal?


Best Regards