The LM2990 is a three-terminal, low-dropout, 1-A negative voltage regulator available
with fixed output voltages of −5 V, −5.2 V, −12 V, and −15 V.
The LM2990 uses circuit design techniques to provide low-dropout and low-quiescent
current. The dropout voltage at 1-A load current is typically 0.6 V and an ensured worst-case
maximum of 1 V over the entire operating temperature range. The quiescent current is typically 1 mA
with 1-A load current and an input-output voltage differential greater than 3 V. 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 ≤ 3 V).
Output voltage accuracy is ensured to ±5% over load and temperature extremes.
The LM2990 also implements short-circuit proof, and thermal shutdown includes hysteresis
to enhance the reliability of the device when overloaded for an extended period of time.
All these features make the LM2990 an ideal negative power supply suited for dual supply
systems. The device may also be used as fixed or adjustable current sink load.
The LM2990 is available in two 3-pin packages and is rated for operation over the
junction
temperature range of −40°C to 125°C.
