I have the hardware LDAC pin tied to Vdd, I.e. high. When I write data to a DAC input register, no output occurs (command 0001). If I then update the DAC’s register (command 0010) the output for that channel occurs. This is expected behaviour. If I bring LDAC pin low, and try command 0001, output occurs immediately. Again, expected behaviour. Reading the datasheet, I can override this behaviour by setting an LDAC mask for a channel to 1 so even if LDAC pin is high, output will occur straightaway. My understanding from the datasheet page 24 is that I send the following to allow channel A to ignore LDAC Pin state:
bits DB23 TO DB20, command: 0101
bits DB19 TO DB16, address: Don’t care, but 0000
bits DB15 TO DB8, data byte: Don’t care, but 00000000
bits DB7 TO DB4, data byte MSB: Don’t care, but 0000
bit DB3 to DB0, data byte LSB: LDAC mask for channels DCBA, so 0001 for channel A to ignore hardware LDAC.
If I do this, I still need to run commands 0001 and 0010 for channel A to get output but I was expecting to just run command 0001. Have I misunderstood something?