1 Features

· Ideal For Highly Efficient Charger Designs For Single-, Two-, or Three-Cell Li-lon and Li-Polymer Battery Packs
· bq24105 Also for LiFePO4 Battery(see Using bq24105 to Charge the LiFePO4 Battery)
· Integrated Synchronous Fixed-Frequency PWM Controller Operating at 1.1 MHz With 0% to 100% Duty Cycle
· Integrated Power FETs for Up To 2-A Charge Rate
· High-Accuracy Voltage and Current Regulation
· Available in Both Stand-Alone(Built-In Charge Management and Control) and System-Controlled (Under System Command) Versions
· Status Outputs for LED or Host Processor Interface Indicates Charge-In-Progress, Charge Completion, Fault, and AC-Adapter Present Conditions
·20-V Maximum Voltage Rating on IN and OUT Pins
· High-Side Battery Current Sensing
· Battery Temperature Monitoring
· Automatic Sleep Mode for Low Power Consumption
· System-Controlled Version Can Be Used in NiMH and NiCd Applications
· Reverse Leakage Protection Prevents Battery Drainage
· Thermal Shutdown and Protection
· Built-In Battery Detection
· Available in 20-Pin,3.50 mm ×4.50 mm VQFN Package
2 Applications
· Handheld Products
· Portable Media Players
· Industrial and Medical Equipment
· Portable Equipment
3 Description 
The bqSWITCHERTM series are highly integrated Liion and Li-polymer switch-mode charge management devices targeted at a wide range of portable applications. The bqSWITCHERTM series offers integrated synchronous PWM controller and power FETs, high-accuracy current and voltage regulation, charge preconditioning, charge status, and charge termination, in a small, thermally enhanced VQFNpackage. The system-controlled version provides additional inputs for full charge management under system control.
The bqSWITCHERTM charges the battery in three phases: conditioning, constant current, and constant voltage. Charge is terminated based on userselectable minimum current level.A programmable charge timer provides a safety backup for charge termination. The bqSWITCHERTM automatically restarts the charge cycle if the battery voltage falls below an internal threshold. The baSWITCHERTM automatically enters sleep mode when Vcc supply is removed.

Feature

(Picture: Pinout)