LP3809 is a series of high precision voltage detector with ultra low current consumption (500nA typ. at Vdd=3.0V). It can work at very low voltage, which makes it perfect for system reset. LP3809 is composed of high precision voltage reference, comparator, delay circuit, output driver and resistor array. Internally preset detect voltage has a low temperature drift and requires no external trimming. Two types of output, CMOS and N-channel open-drain are available.LP3809 is available in SOT-23-3 packages which are Pb free.