The supervisory circuit NCP303LSN16T1GNCP302 and NCP303 series are the second generation ultra-low current and voltage detectors, and the supervisory circuit NCP303LSN16T1G contains a programmable delay generator. These devices are specifically designed to be used as reset controllers in portable microprocessor-based systems where extended battery life is critical. Each series features a high precision brownout detector with hysteresis and an externally programmable delay generator. This combination of functions prevents unstable system reset operations. The supervisory circuit NCP303LSN16T1G series consists of complementary output devices that can use active high reset or active low reset. The NCP303 series features an open drain N-channel output and an active low reset output. Features ? Quiescent Current 0.5 A Typical ? High Accuracy Undervoltage Threshold 2.0%_? Externally Programmable Time Delay Generator ? Wide Operating Voltage Range 0.8 V 10 V ? Complementary or Open Drain Output ? Active Low or Active High Reset ? C +125°C Temperature Range (Except for Voltage Options from 0.9 to 1.1 V) ? NCV Prefix Automotive and Other Applications Requiring Unique Site and Control Change Requirements; AEC? Q100 qualified, strong PPAP capability? These devices are lead free and RoHS compliant Standard typical applications? Microprocessor reset controller? Low battery detection? Power failure indicator? Battery backup detection

Supervisory Circuit The NCP303LSN16T1G series devices consist of a precision voltage detector that drives a delay generator. Figures 37 and 38 show a timing diagram and a typical application. Consider first that the input voltage Vin is at a nominal level and greater than the voltage detector upper threshold (VDET+). The voltage at pin 5 and capacitor CD will be at the same level as Vin, and the reset output (pin 1) will be high for active low devices and low for active high devices. If a power interruption occurs and Vin is significantly insufficient, the lower detector threshold (VDET?) will be dropped, and the external delay capacitor CD will be immediately released by the internal N? channel MOSFET connected to Pin 5. This sequence of events causes the reset output to be in a low state for an active low device, or a high state for an active high device. After the power outage is complete,

Vin will return to its nominal level again and become larger than VDET+. The voltage detector turns off the N-channel MOSFET and allows the pull-up resistor, RD, to charge the external capacitor, CD, creating a programmable delay for releasing the reset signal. When the voltage at pin 5 exceeds the inverter/buffer threshold (typically 0.675 Vin), the reset output will return to its original state. The reset output delay versus capacitance is shown in Figure 30 - 32. The voltage detector and inverter/buffer have built-in hysteresis to prevent erratic reset operation. Although these device families are designed for use as reset controllers in portable microprocessor-based systems, they provide a cost-effective solution in many applications that require accurate voltage monitoring and time delays.