ADL5317's VPHV Noise

Document created by analog-archivist Employee on Feb 23, 2016
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I have a question about ADL5317's VPHV Noise. Because VPHV is high, I need to
use DC-DC to get the power. Then if the noise at VPHV is about +-0.5mV@500kHz,
will it influence the voltage at VAPD Pin?


The only PSRR data I have for that part was taken at 100 kHz.  At that
frequency, any noise applied to VPHV is attenuated by 17 dB at VAPD (PSRR = 17
dB @ 100 kHz).  That would mean that a ±0.5 mV ripple at VPHV would be reduced
to ~ ±0.07 mV at VAPD.  Assuming that the PSRR at 500 kHz is a little worse,
maybe ~15 dB, ±0.5 mV of noise at VPHV would cause ~ ±0.14 mV noise at VAPD.