DAC81408: About VCC supply

Hello,

An LDO would be the recommended supply for a stable output. Any switching noise from a DCDC regulator will appear on the analog outputs. 

Best,

Katlynne Jones 

Hi,

It depends on the PSRR of the output amplifier and the frequency of the DCDC.  Generally, our devices have limited bandwidth, so noise over ~500kHz should probably be filter externally.  We generally do not see better than -60dB PSRR, so it depends on the magnitude of the supply ripple.  If you know the switching frequency, you can use some techniques to filter just that.  You could improve noise performance by adding more discrete capacitors or series resistors on the supply pins to help attenuate the noise.

Thanks,

Paul