View lm2931.rev5 datasheet:

LM2931 Series Low Dropout Voltage Regulators The LM2931 series consists of positive fixed and adjustable output voltage regulators that are specifically designed to maintain proper regulation with an extremely low input–to–output voltage differential. http://onsemi.com These devices are capable of supplying output currents in excess of 100 mA and feature a low bias current of 0.4 mA at 10 mA output. FIXED OUTPUT VOLTAGE Designed primarily to survive in the harsh automotive environment, these devices will protect all external load circuitry from input fault TO–92 Pin 1. Output conditions caused by reverse battery connection, two battery jump Z SUFFIX 2. Ground starts, and excessive line transients during load dump. This series also CASE 29 3. Input 1 1 2 includes inte