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DAC8771: Errors in datasheet and bad descriptions of bit functions in some registers

Part Number: DAC8771
Other Parts Discussed in Thread: DAC8775,

Hello Guys,

Good day.

During the development with DAC8771-EVM, our customer have detected some errors on the device datasheet. Kindly help to confirm.

1) Page 13, figure 1: The timing diagram should be split to demonstrate the different operation modes (synchronous and asynchronous; LDAC and CLEAR signals behaviours).

2) Page 32, equation 5: The equation has an error, and it has been verified with the development board. It should be:
   I_OUT = 48 mA x (CODE / 2^16) - 24 mA. If not, the codes did not match with the real output for that range.

3)  Page 42, figure 103: It should be a note explaining that it is not necessary to cycle over the 5 registers to update a value, if the same DAC configuration remains.

4) Page 49, table 9: Bit CHA is not completely explained. It should be completed with: "When set, this bit enables the DAC channel (...)".

5)  Page 51, table 12: Bit DCA is not completely explained. It should be completed with: When set, this bit enables the Buck-Boost channel (...)".

Thanks and regards,


  • Hi Art,

    Joe will take a look into this tomorrow.



  • Art,

    1. I think that would be best to really split this timing diagram into four cases (one for each transition of VOUT. /LDAC=0 is really asynchronous mode, where the /LDAC is low all the time. /LDAC with a transition is really synchronous mode where /LDAC transitions after /SYNC goes high. Another split could be for the CLR behavior and timing and yet another split could be for the /RESET timing.

    2. That is correct, the equation 5 should be updated for ±24mA. The equation shown would have been correct for ±20mA.

    3. That is correct. There is a bit extra explanation here. I think this is because the DAC8771 originally comes from the DAC8775, which is a four-channel device. Because there are multiple DACs integrated into that device, you would likely need to configure each DAC separately, which likely means that you would need to go through the entire sequence.

    4 and 5. This CHA and DCA also come from the multi-channel DAC8775. For that device, you would need to select the channel of the DAC or the DC-DC converter to set their configuration. For the DAC8771, this is a single channel device, and you would always select the first channel (here it is labeled as A) as CHA and DCA for programming. For the DAC8771, it would be best just to say set these bits to 1.

    Joseph Wu