MAX8672

www.DataSheet4U.com 19-0653; Rev 0; 11/06 KIT ATION EVALU E L B A AVAIL Complete Backup Management IC for NiMH Batteries General Description Features o o o o o o o o o o Charges 1- or 2-Cell NiMH Backup Batteries Programmable Charge Current DC Trickle Charge Mode for Maximum Cell Life Deep-Recovery Charge Restores Cells < 1V Programmable Charge Timer Programmable Charge-Voltage Limit and Battery UVLO Reverse Current Blocking on BATT, LDO, and Boost—No Diodes Needed No Battery Drain When Off (< 50nA) Thermistor Sensing Disables Standard Charge Battery Restart Charge Threshold Prevents Overcharge MAX8672 The MAX8672 complete power manager for backup batteries in smart devices offers feature-programmable battery charging and main-system backup. The device includes a charger for 1- or 2-cell NiMH backup batteries. A low-quiescent current synchronous-rectified boost converter and LDO supply up to 20mA during system backup. The BST output is internally set to regulate at 3.05V. The MAX8672 LDO is powered from the boost converter output and is adjustable from 1.5V to 3.05V. The MAX8672 features programmable charge current, undervoltage lockout (UVLO), and maximum cell voltage. Charging is controlled by both a timer and thermistor monitor. Battery UVLO prevents excessive battery discharge and keeps inactive-battery drain current below 50nA. In addition, both LDO and boost converter outputs block reverse current so that diodes are not needed when connecting these outputs directly...