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