描述 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 VQFN 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.特性Ideal For Highly Efficient Charger Designs For Single-, Two-, or Three-Cell Li-Ion and Li-PolymerBattery Packsbq24105 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 CycleIntegrated Power FETs for Up To 2-A Charge RateHigh-Accuracy Voltage and Current RegulationAvailable in Both Stand-Alone (Built-In Charge Management and Control) and System-Controlled(Under System Command) VersionsStatus Outputs for LED or Host Processor Interface Indicates Charge-In-Progress, ChargeCompletion, Fault, and AC-Adapter Present Conditions20-V Maximum Voltage Rating on IN and OUT PinsHigh-Side Battery Current SensingBattery Temperature MonitoringAutomatic Sleep Mode for Low Power ConsumptionSystem-Controlled Version Can Be Used in NiMH and NiCd ApplicationsReverse Leakage Protection Prevents Battery DrainageThermal Shutdown and ProtectionBuilt-In Battery DetectionAvailable in 20-Pin, 3.50 mm × 4.50 mm VQFN PackageAPPLICATIONSHandheld ProductsPortable Media PlayersIndustrial and Medical EquipmentPortable EquipmentAll other trademarks are the property of their respective owners