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AD9704 - "powers up in a state that leaves the DAC output nonfunctional".

Question asked by FleetFoot on Dec 11, 2017
Latest reply on May 11, 2018 by deljones

I am currently designing an upgrade to existing equipment that needs an additional DAC. I was going to use the AD9704 but when the datasheet was updated from Rev. B to Rev. C in September this year, the following was added in the "Reference Operation" Section:

 

"The internal 1.0 V band gap reference may on occasion power up in a state that leaves the DAC output nonfunctional. To clear this state, power up again, and check that the voltage on the REFIO pin is within the reference output specifications shown in Table 1 or Table 4. After the internal reference is powered up correctly, it does not fail as long as power is applied."

 

In professional equipment, "power up again" is not acceptable so what would be the closest alternative that doesn't have this fatal flaw?

 

P.S. Table 25 on page 38 indicates that the internal reference can be switched off via SPI command (register 0x00, bit 0). If the DAC powers up and the reference fails, would switching the internal reference off then back on clear the fault?

 

http://www.analog.com/media/en/technical-documentation/data-sheets/AD9704_9705_9706_9707.pdf 

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