I have a problem in initializing AD5737 using SPI communication.
Problem : I tried writing to registers of AD5737 using SPI communication from TMS320F2808 microcontroller. I am able to generate SPI clock pulse on falling edge (according to datasheet) and data is available on SDI line of AD5737 (attached image of oscilloscope of SPI output, conforming data is locked into SDI line on falling edge). I am following the output enabling procedure provided on datasheet of AD5737 pg.no 25( Rev.F), where 24 bit data(i.e corresponding register values according to procedure) is sent on 24 clock pulses with the delay of 100us between each data transmission(i.e SYNC is held high for 100us between each 24bit data transmission). But i am not getting any kind of response from AD5737.As i am completely new to this, please let me know how do i confirm that data is sent from microcontroller is been received by AD5737.
1. After following the output enabling procedure, I tried to check Vboost output but it always remains at input voltage( but Vboost value should be according to configuration done on DC-DC control register values sent through SPI) .
2..I even tried to send only software reset values from microcontroller to SDI of AD5737 (i.e 1C9555 in this case) and checked whether the reset pin held low or not(output at reset pin is unchanged).
3. I tried to readback from AD5737 but no output avaliable on SDO of AD5737.
Please let me know if my approach for configuring AD5737 is proper or not, and provide the solution to verify AD5737 is responding to SPI commands.
I have attached the following for reference:
1. Schematic of AD5737
2.SPI data on oscilloscope.