BQ24765数据手册集成电路（IC）的电池充电器规格书PDF

描述 Description

The bq24765 is a high-efficiency, synchronous battery charger with two integrated 30-mΩ NMOS power MOSFETs, and an integrated input current comparator, offering low component count for space-constraint, multi-chemistry battery charging applications. Input current, charge current, and charge voltage DACs allow for very high regulation accuracies that can be easily programmed by the system power management micro-controller using SMBus. The bq24765 has switching frequency of 700 kHz. The bq24765 charges 2, 3, or 4 series Li+ cells, and is available in a 34-pin, 3.50 mm × 7.00 mm VQFN package. The bq24765 features Dynamic Power Management (DPM) and input power limiting. These features reduce battery charge current when the input power limit is reached to avoid overloading the AC adaptor when supplying the load and the battery charger simultaneously. A high-accuracy current sense amplifier enables accurate measurement of input current from the AC adapter, allowing monitoring the overall system power. If the adapter current is above the programmed low-power threshold, a signal is sent to host so that the system optimizes its power performance according to what is available from the adapter. An integrated comparator allows monitoring the input current through the current sense amplifier, and indicating when the input current exceeds a programmable threshold limit. The bq24765 features a thermal regulation loop to reduce battery charge current when the Tj limit is reached. This feature protects internal power FETs from overheating when charging with high current.

特性 Features

• Integrated Power MOSFETs, NMOS-NMOS, Synchronous Buck Converter
• >95% Efficiency
• Frequency 700kHz Allows Smaller Inductor (5 mm × 5 mm)
• Thermal Regulation Loop for Safety, Limit TJ = 120°C
• Adaptive Driver Dead-time and 99.5% Maximum Effective Duty Cycle
• High-Accuracy Voltage and Current Regulation
• ±0.5% Charge Voltage Accuracy
• ±3% Charge Current Accuracy
• ±3% Adapter Current Accuracy
• ±2% Input Current Sense Amp Accuracy

• Integration
• Integrated Power MOSFETs
• Input Current Comparator
• Internal Soft-Start

• Safety
• Thermal Regulation Loop and Thermal Shutdown
• Dynamic Power Management (DPM)
• Power FETs Over Current Protection

• 7 V–24 V AC/DC-Adapter Operating Range
• Simplified SMBus Control
• Charge Voltage DAC (1.024 V–19.2 V)
• Charge Current DAC (128 mA–8.064 A)
• Adapter Current Limit DPM DAC (256 mA–11.008 A)

• Status and Monitoring Outputs
• AC/DC Adapter Present With Adjustable Voltage Threshold
• Input Current Comparator, With Adjustable Threshold and Hysteresis
• Current Sense Amplifier for Current Drawn From Input Source

• Charge Any Battery Chemistry: Li+, LiFePO4, NiCd, NiMH, Lead Acid (2, 3, and 4 Li-Ion Cells)
• Charge Enable Pin (CE)
• Energy Star Low Iq
• Removed
• Present and Charge Disabled

• 34-pin, 3.50 mm × 7.00 mm QFN Package
• APPLICATIONS
• Notebook and Ultra-Mobile Computers
• Portable Data-Capture Terminals
• Portable Printers
• Medical Diagnostics Equipment
• Battery Bay Chargers
• Battery Back-up Systems

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