ReverseSpannung

ReverseSpannung is a term used in electronics to describe the voltage applied across a device in the direction that opposes its normal, forward-conduction path. It is most commonly discussed in relation to diodes, where reverse voltage is the blocking voltage that prevents significant current flow. The concept is also relevant for other components, such as transistors and electrolytic capacitors, where improper polarity or excessive reverse voltage can cause damage.

In a diode, applying ReverseSpannung increases the width of the depletion region and greatly reduces current, ideally to zero. Real devices exhibit a small leakage current that grows with temperature. Devices have a specified maximum reverse-voltage rating, often called peak inverse voltage (PIV) or reverse-voltage rating. Exceeding this rating can lead to breakdown, permanent damage, or unwanted conduction. Some diodes are designed to operate in reverse with controlled breakdown (for example, Zener diodes), while standard rectifiers are not.

Outside diodes, ReverseSpannung also matters for electrolytic capacitors and transistor junctions. Electrolytic capacitors are particularly sensitive to reverse polarity; applying reverse voltage can degrade insulation, cause electrolyte reactions, or vent the component. In transistors, reverse voltages between terminals can affect operation or cause breakdown if limits are exceeded. Designers account for ReverseSpannung by selecting components with adequate reverse-voltage ratings, incorporating protection networks, and ensuring proper polarity in supply rails.

See also: reverse bias, breakdown voltage, leakage current, PIV, rectifier, Zener diode.