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DAC53608: Queries for DAC53608 for voltage margin application

Part Number: DAC53608

Hi,

I am using DAC53608 for voltage margining. Few queries:

1. what's the meaning of "start in a power down to 10k state"? does it mean after VDD ramps up and before write commands, the DAC output (VOUTA-VOUTH) is high-z, while internally it pulls down to GND through 10k? if not, what's the VOUTA-H voltage by default under "power down to 10k mode"?

2. if write the power up command, will OUTA-OUTH output any voltage by default? at this moment, the 10k pull-down is disconnected, right?

3. if the 10k pull down impact the voltage margin calculation? eg. R3, VDAC, etc.

4. could you provide the detailed procedure to implement v-margin? in my application, DAC will be powered up by a standby supply, while the power regulator powers up later.

Thanks.

  • Hi,

    1. what's the meaning of "start in a power down to 10k state"? does it mean after VDD ramps up and before writing commands, the DAC output (VOUTA-VOUTH) is high-z, while internally it pulls down to GND through 10k? if not, what's the VOUTA-H voltage by default under "power down to 10k mode"?

             At power-up, all output channels buffer amplifiers start in power down to 10K mode until a power-up command is issue by writing 0 to the per-channel power down registers. This 10K has  +/-20% tolerance, so at power down, your calculations can go wrong

     2. if write the power-up command, will OUTA-OUTH output any voltage by default? at this moment, the 10k pull-down is disconnected, right?

    At power-up, 10K will be disconnected.

    3. if the 10k pull-down impact the voltage margin calculation? eg. R3, VDAC, etc.

    Only in the power downstate, you need to include 10K, since this will come in parallel with external resistors in the feedback of external converter.

    Please have a look at application notes which describes power supply margining using DAC53608.

    https://www.ti.com/lit/an/sbaa342a/sbaa342a.pdf?ts=1594275403373&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FDAC53608

    Please note that if you need high accuracy margining, we do have newer devices which are targeted for these applications. I will take up this query offline and will contact you through email.

    Regards,

    AK