Referenzspannungsversorgung

Referenzspannungsversorgung, often shortened to reference voltage supply or simply voltage reference, is a fundamental electronic circuit or device that provides a stable, constant voltage output regardless of variations in input voltage, temperature, or load conditions. This stable output is crucial for many analog and mixed-signal electronic systems where precise voltage levels are required for accurate operation.

The primary function of a reference voltage supply is to act as a stable benchmark. In analog-to-digital converters (ADCs), for example, the reference voltage determines the full-scale input range. Any fluctuation in the reference voltage directly translates to a proportional error in the digital output. Similarly, in digital-to-analog converters (DACs), the reference voltage sets the maximum output voltage.

Various technologies are employed to create stable reference voltages. Zener diodes, when operated in their breakdown region, exhibit a relatively stable voltage drop, making them a simple and common choice for less demanding applications. More sophisticated solutions utilize bandgap references, which exploit the temperature dependency of semiconductor junctions to achieve excellent stability over a wide temperature range. Temperature-compensated Zener diodes and buried Zener diodes are also used for higher precision.

The key performance metrics for a reference voltage supply include its accuracy, stability over temperature (temperature coefficient), stability over time (long-term drift), and its ability to maintain voltage under varying load currents (load regulation). Low noise and high power supply rejection ratio (PSRR) are also desirable for sensitive applications. Reference voltage supplies are indispensable components in measurement instruments, power management circuits, sensor interfaces, and communication systems.