General Description The LM2990 is a three-terminal, low dropout, 1 ampere negative voltage regulator available with fixed output volt- ages of −5, −5.2, −12, and −15V. The LM2990 uses new circuit design techniques to provide ow dropout and low quiescent current. The dropout voltage at 1A load current is typically 0.6V and a guaranteed worst-case maximum of 1V over the entire operating tem- perature range. The quiescent current is typically 1 mA with 1A load current and an input-output voltage differential greater than 3V. A unique circuit design of the internal bias supply limits the quiescent current to only 9 mA (typical) when the regulator is in the dropout mode (VOUT −VIN ≤ 3V). Output voltage accuracy is guaranteed to ±5% over load, and temperature extremes. The LM2990 is short-circuit proof, and thermal shutdown in- cludes hysteresis to enhance the reliability of the device when overloaded for an extended period of time. The LM2990 is available in a 3-lead TO-220 package and is rated for operation over the automotive temperature range of −40˚C to +125˚C. Features n 5% output accuracy over entire operating range n Output current in excess of 1A n Dropout voltage typically 0.6V at 1A load n Low quiescent current n Internal short circuit current limit n Internal thermal shutdown with hysteresis n Functional complement to the LM2940 series Applications n Post switcher regulator n Local, on-card, regulation n Battery operated equipment