描述The LM2991 is a low dropout adjustable negative regulator with a output voltage range between ?2V to ?25V. The LM2991 providesup 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 temperaturecoefficient precision reference. The dropout voltage at 1A load current is typically 0.6V and a guaranteed worst-case maximumof 1V over the entire operating temperature range. The quiescent current is typically 1 mA with a 1A load current and an input-outputvoltage differential greater than 3V. A unique circuit design of the internal bias supply limits the quiescent current toonly 9 mA (typical) when the regulator is in the dropout mode (VO ? VI≤?3V).The LM2991 is short-circuit proof, and thermal shutdown includes hysteresis to enhance the reliability of the device wheninadvertently overloaded for extended periods.特性 Output voltage adjustable from ?2V to ?25VOutput current in excess of 1ADropout voltage typically 0.6V at 1A loadLow quiescent currentInternal short circuit current limitInternal thermal shutdown with hysteresisTTL, CMOS compatible^ON/OFF switchFunctional complement to the LM2941 series