AMC7834EVM: DAC output does not update

ivan h

Part Number: AMC7834EVM

I tried changing the DAC output but will it not update on the board. However, I can set the range and the output voltage will change to the range's minimum.

I'm using the external supply for the required voltages, using J11, J10, J9, J8.

over 7 years ago

0 Kevin Duke over 7 years ago

TI__Mastermind 46290 points

Ivan,

Are you interfacing the board with your own software / controller platform or is this a problem you're facing with the EVM GUI?

If you are interfacing the board on your own, are you in "open-loop" mode and if so what are you doing with the !DACTRIG pin?

0 Paul_Frost over 7 years ago in reply to Kevin Duke

TI__Guru 53623 points

Hi Ivan,

Note that on this device there are three methods of updating the DAC output after the data has been written to the DAC register. The first is to use the DACTRIG pin as Kevin mentioned. The other is to set the sync mode for the DAC. Using the DAC Sync Register (0x15) the DACs can be synchronous, meaning that the DACTRIG pin must be set low or the DAC/ADC Trigger Register (0x1C) must be written to to update the DACs. Setting the DACs to asynchronous mode means the DACs will update once the value is written to their buffer registers.

Thanks!
Paul