MIC2779 Datasheet | Micrel Semiconductor

Micrel Voltage Monitor with Adjustable Hysteresis Preliminary Information General Description The MIC2779 is a voltage monitor- uniquely designed to detect two separate voltage thresholds- bined with a delay generator and logic. It is designed for monitoring the battery supply of portable digital systems, particularly PDAs, pagers, and cellular telephones. High- and low-voltage thresholds can be adjusted independently, allowing for wide hysteresis. Voltage detection thresholds are accurate to 2%. If the battery voltage falls below the low-voltage threshold, the output /RST or RST is asserted and latched, preventing system operation until the battery is replaced or recharged. Internal logic prevents the output from chattering due to battery recovery or load removal. The output is asserted for 140ms (minimum) when a fresh battery is inserted. For applications requiring open-drain output, see MIC2778/ MIC833. The IC’s power supply input is separate from the detector inputs, allowing the MIC2779 to be powered from a downstream supply, such a boost converter. Supply current is extremely low (1µA, typical), making it ideal for portable applications. A high-precision 1% grade is available. The MIC2779 is supplied in Micrel’s Itty Bitty™ 5-lead SOT-23-5 package. Features - Optimized for PDAs, cellular telephones, pagers, and other battery-powered devices - Independently adjustable high- and low-voltage thresholds - Internal logic prevents battery-voltage-fluctuation chatter - High ± 2% voltage threshold accuracy; 1% available - Built in 140ms (minimum) delay deglitches output - Extremely low 1µA typical supply current - For applications requiring open-drain output, see MIC2778/MIC833 - Immune to brief power supply transients - 5-lead SOT-23 package Applications - - - - - - PDAs Pagers Cordless phones Consumer electronics Embedded controllers Personal electronics Typical Application MIC5207-3.0BM5 IN Li-Ion Cell 604k 1% 56k 1% 340k 1% MIC2779L VDD LTH...