LTC4150

FEATURES n Indicates Charge Quantity and Polarity n ±50mV Sense Voltage Range n Precision Timer Capacitor or Crystal Not Required n 2.7V to 8.5V Operation n High Side Sense n 32.55Hz/V Charge Count Frequency n 1.5μA Shutdown Current n 10-Pin MSOP Package APPLICATIONS n Battery Chargers n Palmtop Computers and PDAs n Cellular Telephones and Wireless Modems TYPICAL APPLICATION LTC4150 Coulomb Counter/ Battery Gas Gauge DESCRIPTION The LTC®4150 measures battery depletion and charging in handheld PC and portable product applications. The device monitors current through an external sense resistor between the battery’s positive terminal and the battery’s load or charger. A voltage-to-frequency converter transforms the current sense voltage into a series of output pulses at the interrupt pin. These pulses correspond to a fixed quantity of charge flowing into or out of the battery. The part also indicates charge polarity as the battery is depleted or charged. The LTC4150 is intended for 1-cell or 2-cell Li-Ion and 3-cell to 6-cell NiCd or NiMH applications. L, LT, LTC, LTM, Linear Technology, the Linear logo, Burst Mode are registered trademarks and ThinSOT and PowerPath are trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. RSENSE + CHARGER LOAD 4.7μF 4.7μF SENSE– SENSE+ CF+ CF– LTC4150 GND VDD INT CLR POL SHDN CHG RL RL DISCHG μP 4150 TA01a ERROR (% FULL SCALE) Integral Nonlinearity, % of Full Scale 0.5 0.4 0...