To whom it may concern,
I'm trying to control two daisychained DAC088S085 via SPI protocol. Right now on a PCB I only connected one device with Va =Vref1=5V, MOSI, CLK and SS, the analog outs are not loaded. Here the specific of my communication protocol: SPIMODE1, MSBFIRST, fclock = 14MHz, CS active LOW.
As a test, I would like to see the analog output changing according to my code and see Dout1, for testing the daisychain method. After I sent to the device the 1001000000000000, to switch it to WTM mode, I would expect the analog outs to change as I send the commands, but I don't see the voltage on the outs changing. Furthermore Dout1 appears to be somewhat out of sync (more clear explanation in the pictures below). What am I doing wrong?
In this image I'm sending to the VoutD of DAC1 the number 178 (16 bits 00111011 00100000) and to VoutD of DAC2 the number 102 (00110110 01100000). Looking at the Dout1 I can see it copies the first input and sends it to the second 16-bits block instruction as expected, apart from one bit (in the first 16 block, highlighted with a question mark in the picture) and the Dout1 high value less than 2V. Are these normal? Moreover what is more confusing is shown in this second picture, which is simply a zoomed in version of the third 8-bits instruction. It is possible to see how the in from the master is synced correctly to the falling edge of the clock (red dashed line), while Dout1 seems to be synced with the rising edge (green dashed line), what is going on? Any help would be appreciated