| Output options | Adjustable Output, Negative Output |
| Iout (Max) (A) | 1 |
| Vin (Max) (V) | 0.3 |
| Vin (Min) (V) | -26 |
| Vout (Max) (V) | -3 |
| Vout (Min) (V) | -24 |
| Fixed output options (V) | 0 |
| Noise (uVrms) | 200 |
| Iq (Typ) (mA) | 0.7 |
| Thermal resistance θJA (°C/W) | 28 |
| Rating | Military |
| Load capacitance (Min) (μF) | 1 |
| Regulated outputs (#) | 1 |
| Features | Enable |
| Accuracy (%) | 5 |
| PSRR @ 100 KHz (dB) | 22 |
| Dropout voltage (Vdo) (Typ) (mV) | 600 |
| Operating temperature range (C) | -55 to 125, -40 to 85 |
The LM2991 is a low dropout adjustable negative regulator with a output voltage range between ?2V to ?25V. The LM2991 provides up to 1A of load current and features a ^On /Off pin for remote shutdown capability.
The LM2991 uses new circuit design techniques to provide a low dropout voltage, low quiescent current and low temperature coefficient precision reference. The dropout voltage at 1A load current is typically 0.6V and a guaranteed worst-case maximum of 1V over the entire operating temperature range. The quiescent current is typically 1 mA with a 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 (VO ? VI
The LM2991 is short-circuit proof, and thermal shutdown includes hysteresis to enhance the reliability of the device when inadvertently overloaded for extended periods.