Measurement setup for the thermal and line regulation characteristics of reference voltage sources

Abstract

Paper presents universal test stand utilized for testing functional parameters of a reference voltage source based on Zener diode. The stability of the standard is crucial during the operation of precise voltage A/D converters. Value of the output voltage from the reference source may change in the function of the operating temperature or due to the variation of power supply. Presented test stand allows to determine the thermal and line regulation characteristics of the tested element. Test stand is based on differential measurement, where the output voltage from the tested element is compared with the voltage from the reference element kept in a stable conditions. Tested element can be exposed to the temperature variation or to the changes of power supply voltage. Output voltage from the differential circuit as well as a value of an influential factor (operating temperature or supply voltage) is continuously measured and logged. Based on obtained characteristics optimal working conditions for tested elements can be identified. It also allows proper selection of the most stable specimens for the crucial applications.