Shuntreferenzen

Shuntreferenzen, often translated as shunt references, are electronic circuits designed to produce a stable and precise voltage independent of variations in supply voltage, temperature, or load current. They are a crucial component in many analog and mixed-signal integrated circuits, particularly in applications requiring accurate voltage levels for biasing, signal processing, or analog-to-digital conversion.

The core principle behind most shunt references involves a device that exhibits a relatively stable voltage drop over a wide range of operating conditions. This could be a Zener diode, a bandgap reference, or a more complex combination of transistors and resistors. The "shunt" aspect refers to how these devices are typically connected in parallel with the load, effectively shunting excess current away to maintain the desired output voltage.

A common implementation uses a Zener diode. When current flows through the Zener diode in its breakdown region, it maintains a nearly constant voltage across itself. This voltage is then used as the reference. However, Zener diodes can suffer from temperature drift and noise. More advanced shunt references employ bandgap references, which leverage the opposing temperature coefficients of different semiconductor junctions to achieve excellent temperature stability.

The performance of a shunt reference is characterized by several key parameters: output voltage accuracy, temperature coefficient (how much the output voltage changes with temperature), line regulation (how much the output voltage changes with supply voltage variations), and load regulation (how much the output voltage changes with load current variations). These specifications are critical for designers choosing a shunt reference for a particular application.