ACT  -  系列元器件数据手册
ACT8700  -  Four Channel Integrated Power Management IC for Handheld Portable Equipment  -  Active Semi  -  电源管理

FEATURES
? Multiple Patents Pending
? Li+ Battery Charger with Integrated MOSFET
? ON/OFF Control and Status Indication
? Three Integrated Regulators
? 350mA PWM Step-Down DC/DC
? 500mA PWM Step-Down DC/DC
? Step-Up DC/DC with OVP for WLED Bias
? Minimal External Components
? 4x4mm, Thin-QFN (TQFN44-24) Package
? Only 0.75mm Height
? RoHS Compliant
APPLICATIONS
? Portable Devices and PDAs
? Digital Media Players
? Battery Operated Devices
? GPS Receivers, etc.
GENERAL DESCRIPTION
The patent-pending ACT8700 is a complete, costeffective,highly-efficient ActivePMUTM power management solution that is ideal for a wide range of portable handheld equipment. This device integrates two step-down DC/DC converters, one stepup DC/DC converter with over-voltage protection (OVP) for WLED bias, and a full-featured, linearmode Li+ battery charger-into a single, thin, spacesaving package.
REG1 and REG2 are fixed-frequency, current-mode PWM step-down DC/DC converters that are optimized for high efficiency and are capable of supplying up to 350mA and 500mA, respectively. REG3 is a fixed-frequency, step-up DC/DC converter that safely and efficiently biases a string of up to seven white-LEDs for backlighting. The battery charger incorporates an internal power MOSFET for constant-current/constant-voltage,  hermally regulated charging of a single-cell Li+ battery.
The ACT8700 is available in a tiny 4mm x 4mm 24-pin Thin-QFN package that is just 0.75mm thin.