| 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 |
| Noise (uVrms) | 200 |
| Iq (Typ) (mA) | 0.7 |
| Thermal resistance θJA (°C/W) | 28 |
| Rating | Catalog |
| 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) | -40 to 125 |
- Output Voltage Adjustable from ?3 V to ?24 V, Typically ?2 V to ?25 V
- Output Current in Excess of 1 A
- Dropout Voltage Typically 0.6 V at 1-A Load
- Low Quiescent Current
- Internal Short Circuit Current Limit
- Internal Thermal Shutdown With Hysteresis
- TTL, CMOS Compatible ON/OFF Switch
- Functional Complement to the LM2941 Series
The LM2991 is a low dropout adjustable negative regulator with a output voltage range between ?3 V to ?24 V. The LM2991 provides up to 1 A 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 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 a 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).
The LM2991 is short-circuit proof, and thermal shutdown includes hysteresis to enhance the reliability of the device when inadvertently overloaded for extended periods. The LM2991 is available in 5-lead TO-220 and DDPAK/TO-263 packages and is rated for operation over the automotive temperature range of ?40°C to +125°C. Mil-Aero versions are also available.