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DAC5573: Can I switch the 4 internal DACs independently to High-Z output?

Andreas Kleiner
Prodigy 30 points
Part Number: DAC5573
Other Parts Discussed in Thread: DAC53004, DAC63004,

Is it possible to switch the PowerDown modes (via PD0, PD1 and PD2 bits) independently per channel on the DAC5573 (or DAC63004/DAC53004)?

As example - Is it possible to get the following output voltages/High-Z's at the same time: Vout A to 2.5 V, Vout B to High-Z, Vout C to 2.5 V and Vout D to High-Z (with Vref = VDD = 5V)?

As I understand the register description in the datasheet on page 16 (DAC5573), this should work.

However, this is not explicitly mentioned in the description of the "Power-Down Modes" on page 23-24 (DAC5573).

 

Same question for DAC63004/DAC53004.

  • 0
    TI__Mastermind 30818 points

    Hi Andreas, 

    Yes, you're right. Table 2 shows that the power down setting can be applied to the channels individually using the sel1 and sel0 bits in the control byte. The power down mode is set in MSB7 and MDB6 (modes described in table 8 on page 24)

    Yes, the DACx3004 channels can also individually be set in power down mode using the different fields in the COMMON-CONFIG register (register 0x1F). 

    Best,

    Katlynne Jones 

  • 0 in reply to Katlynne Jones
    Prodigy 30 points

    Hi Katlynne,

    thank you for the answer. Yes from the datasheet it looks like it will work, but had somebody really tested it with an Evaluation-Board?
    I have bad experience with a 4 channel DAC from another manufacturer! With this part it was the same, from the datasheet description I assumed that it should work, but it does not.
    The PowerDown bits in the registers of this DAC are also per DAC channel but the analog switches which set the outputs to High-Z are set by a common signal for all 4 channels. So I can only switch all 4 outputs together to High-Z or none of them.
    An output configuration like: Vout A to 2.5 V, Vout B to High-Z, Vout C to 2.5 V and Vout D to High-Z is not possible with this DAC.

    Are the DAC5573 or DAC63004/DAC53004 really able to provide independent output settings with mixed voltage and High-Z outputs at the same time?
    Is it possible that someone at TI test it with an Evaluation-Board?

    Kind regards,
    Andreas

  • 0 in reply to Andreas Kleiner
    TI__Mastermind 30818 points

    Hi Andreas, 

    I have used the DACx3004 many times and know that the power down mode of the output channels can be set independently. 

    I can check on the DAC5573, but I do not have an EVM on hand so there would be a delay while I wait for one to come in. Let me know if you are interested. 

    Best,

    Katlynne 

  • 0 in reply to Katlynne Jones
    Prodigy 30 points

    Hi Katlynne,

    thank you for the clear answer for the DACx3004.
    Yes, I am interested to know if the DAC5573 behave equal. This is my favourite and I need the independent setting of the High-Z feature.

    Kind regards,
    Andreas

  • 0 in reply to Andreas Kleiner
    TI__Mastermind 30818 points

    Hi Andreas, 

    Ok. I've ordered the board and it should arrive it by sometime next week. I will let you know when I have the test results. 

    Best,

    Katlynne Jones 

  • 0 in reply to Katlynne Jones
    TI__Mastermind 30818 points

    Hi Andreas, 

    I confirmed on the EVM that you can configure the powerdown settings independently per channel. 

    Best,

    Katlynne Jones 

  • 0 in reply to Katlynne Jones
    Prodigy 30 points

    Hi Katlynne,

    thank you so much for the test.
    Only for verification, is it sure that the outputs 1 and 3 are really High-Z and not only driven 0 V?

    Kind regards
    Andreas

  • +1 in reply to Andreas Kleiner
    TI__Mastermind 30818 points

    Hi Andreas, 

    Yes, the outputs are Hi-Z. I could pull them up with an external pullup resistor.

    I'm not able to get to the lab for the rest of the week, so unfortunately I'm unable to provide another screenshot right now.

    Best,

    Katlynne Jones 

  • 0 in reply to Katlynne Jones
    Prodigy 30 points

    Thank you Katlynne!

    If you have pulled them up with a resistor, I believe you and don't need a screenshot.

    Kind regards
    Andreas