The LP2957 is a 5V micropower voltage regulator with electronic shutdown, error flag, very low quiescent current (150 µA typical at 1 mA load), and very low dropout voltage (470 mV typical at 250 mA load current). Output can be wired for snap-on/snap-off operation to eliminate transition voltage states where µP operation may be unpredictable. Output crowbar (50 mA typical pull-down current) will bring down the output quickly when the regulator snaps off or when the shutdown function is activated. The part has tight line and load regulation (0.04% typical) and low output temperature coefficient (20 ppm/°C typical). The accuracy of the 5V output is ensured at room temperature and over the full operating temperature range. The LP2957 is available in the five-lead TO-220 and DDPAK/TO-263 packages.