The SPX3940/41/42 is a low power voltage regulator. This device is an excellent choice for battery-powered applications such as cordless telephones, radio control systems and portable computers. The SPX3940/41/42 features very low quiescent current (100A Typ.) and very low dropout voltage. This includes a tight initial tolerance of 1% max and 2% max., and very low output temperature coefficient, making the SPX3940/41/42 useful as a low-power voltage reference. The error flag output feature is used as power-on reset for warning of a low output voltage, due to a falling voltage input of batteries. Another feature is the logic-compatible shutdown input which enables the regulator to be switched on and off. The SPX3940/41/42 is offered in 3-pin and 5-pin TO-220 package SOT-223, and surface mount TO-263 packages. The regulator output voltage (of the 8-pin SO-8 and 5-pin TO-220 & TO-263) may be pin-strapped for a 3.3V or programmed from 1.24V to 29V with an external pair of resistors.