Analysis of the voltage reference fluctuations of subsurface zener diodes

Voltage fluctuations of subsurface Zener diodes are analyzed from the point of view of voltage references for A/D and D/A converters. Based on the experimental dependence of the noise voltage spectral density of subsurface Zener diodes on the reverse current, the probability density and the probability distribution functions are computed and illustrated. From the results obtained it is possible to determine the A/D or D/A conversion bits, which have the transition level, with a defined probability, lower than or equal to the fluctuation of the voltage reference.