MAX8672 Datasheet | Maxim Integrated

Description Features o o o o o o o o o o Charges 1- or 2-Cell Ni MH 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 (< 50n A) Thermistor Sensing Disables Standard Charge Battery Restart Charge Threshold Prevents Overcharge The MAX8672 plete 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 Ni MH backup batteries. A low-quiescent current synchronous-rectified boost converter and LDO supply up to 20m A 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 50n A. In addition, both LDO and boost converter outputs block reverse current so that diodes are not needed when connecting these outputs directly to system supplies. The MAX8672 requires that a valid system supply be present before system backup operation can occur. The MAX8672 is available in a 14-pin, 3mm x 3mm TDFN package and is rated for -40°C to +85°C operation. Ordering Information PART MAX8672ETD+T PIN-PACKAGE 14 TDFN-14 (3mm x 3mm) PKG CODE T14334+2 The MAX8672 operates in the -40°C to +85°C extended operating temperature range. +Denotes lead-free package. Applications PDA, Palmtop, and Wireless Handhelds Smart Cell Phones Typical Operating Circuit CT THRM Pin Configuration THRM CHGV 2.7V TO 5.5V INPUT CHGV DR GND LDO TOP VIEW CHGI...