7912

7912 is a fixed negative voltage regulator in the 79xx family. It provides a regulated -12 V output relative to ground from a more negative input supply. It is the negative counterpart to the positive 7812 regulator and is used to generate the negative rail in dual-supply circuits.

The regulator maintains -12 V as long as the input remains sufficiently negative (typically up to -35 V maximum). Dropout voltage is typically about 2 V at moderate load, so input should be around -14 V or lower for proper regulation. Maximum output current is commonly around 1 A, depending on thermal conditions; power dissipation requires adequate heatsinking. Typical regulators include overcurrent protection and thermal shutdown.

Pinout and capacitors: In the common TO-220 package with the front facing the user, pins from left to right are Ground, Input, Output. A small ceramic or film capacitor on the input (around 0.33 µF) and a capacitor on the output (around 0.1 µF or larger) are recommended to ensure stability and transient response.

Variants and packaging: The device appears as LM7912, UA7912, KA7912, and equivalents from many manufacturers. Available in TO-220, and other packages such as TO-3 or surface-mount variants in modern lines.

See also: LM7812, 79xx family, linear regulators.