Switch Mode Charger Li-Ion/Li-Pol/NiMH/NiCD Packs 150mA to 2000mA 2.1V to 15.5V 20-Pin VQFN EP T/R

The bqSWITCHER series are highly integrated Li-ion and Li-polymer switch-mode charge management devices targeted at a wide range of portable applications. The bqSWITCHER 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 QFN package. The system-controlled version provides additional inputs for full charge management under system control. The bqSWITCHER charges the battery in three phases: conditioning, constant current, and constant voltage. Charge is terminated based on user- selectable minimum current level. A programmable charge timer provides a safety backup for charge termination. The bqSWITCHER automatically restarts the charge cycle if the battery voltage falls below an internal threshold. The bqSWITCHER automatically enters sleep mode when VCC supply is removed.

Ideal For Highly Efficient Charger Designs For Single-,
Two- or Three-Cell Li-Ion 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, 3,5 mm × 4,5 mm QFN Package

APPLICATIONS

• Handheld Products
• Portable Media Players
• Industrial and Medical Equipment
• Portable Equipment