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Original question:

DAC81416: DAC81416 Vcc positive power minimum requirements

DAC81416: Minimum Vcc spec

Andrew Kirby1
Prodigy 175 points
Part Number: DAC81416

Datasheet says the minimum reccomended operating Vcc is 9V, however it also says that the absolute minimum can go lower. 

What would happen if I operated this device from +/-6V - what other specifications would be affected?

I see previously when this was asked, you requested the author state the output current and operating temperature. In this case we would be using only 8 outputs and the max current from each would be 1mA. (Sadly the original author never answered back, so the question was closed without answer). This would be operating in an industrial environment - but let me turn the question around and ask - what temperature range would we need to keep to enable running on +/-6V rails.

Andy

  • 0
    Prodigy 175 points

    Further Info: Have tried this out in practice and it seems +/-2.5 and +/-5.0 ranges produce a correct-looking* output with +/- 6v rails. Reducing the rails down to 5.2V there was some clipping of the sinusoidal +/-FS test output.   

    * This means it looked roughly like a sine wave with expected min/max values. 

    The question remains what specs am I compromising by doing this?

  • 0 in reply to Andrew Kirby1
    TI__Guru 53283 points

    Hi Andrew,

    The main spec that is compromised is current output capability.  The output amplifier requires headroom and loading the output can cause internal nodes to "droop" to a lower voltage.  This can be worse at temperature extremes as well.

    Internally, we also require some voltage headroom for the analog switches in the R2R ladder of the DAC itself.  We sometimes see leakage current if the supply does not have sufficient headroom, and that can cause linearity errors.

    Ultimately, we do not recommend that you use <9V, but in practice your performance might be acceptable.  We do not have validation data for all of the specs at 6V, so we cannot guarantee any performance values.

    Thanks

    Paul