SMBus Controlled Battery Charger with Integrated FETs 34-VQFN -40 to 155# BQ24765RUVT Technical Documentation
## 1. Application Scenarios
### Typical Use Cases
The BQ24765RUVT is a high-efficiency, synchronous battery charge controller and system power selector designed for 2-4 series Li-ion/Li-polymer battery packs . Primary applications include:
- Portable Computing Devices : Notebooks, ultrabooks, and tablet PCs requiring smart battery charging
- Medical Portable Equipment : Handheld diagnostic devices and mobile monitoring systems
- Industrial Handheld Terminals : Ruggedized mobile computers and barcode scanners
- Professional Audio/Video Equipment : Portable recording devices and broadcast equipment
### Industry Applications
- Consumer Electronics : High-performance laptops and premium tablets
- Healthcare : Battery-powered medical devices requiring reliable charging
- Industrial Automation : Mobile data collection terminals and portable test equipment
- Telecommunications : Field service equipment and portable communication devices
### Practical Advantages
- High Integration : Combines charging, power path management, and system monitoring
- Efficiency : Up to 97% efficiency with synchronous switching architecture
- Flexible Input : Supports 5-24V adapter input range
- Smart Power Management : Automatic power source selection between adapter and battery
- Safety Features : Comprehensive protection including over-voltage, over-current, and thermal shutdown
### Limitations
- Battery Chemistry : Limited to Li-ion/Li-polymer chemistries only
- Series Configuration : Requires 2-4 series cell configurations
- External Components : Needs external MOSFETs and sense resistors
- Thermal Management : Requires proper heatsinking for maximum charging currents
## 2. Design Considerations
### Common Design Pitfalls and Solutions
Pitfall 1: Inadequate Thermal Management
- Issue : Overheating during high-current charging
- Solution : Implement proper PCB copper pours and consider thermal vias
Pitfall 2: Incurrent Current Sensing
- Issue : Inaccurate charging current measurement
- Solution : Use 1% tolerance sense resistors and proper Kelvin connections
Pitfall 3: Input Voltage Transients
- Issue : Damage from adapter plug/unplug events
- Solution : Implement TVS diodes and input capacitors close to IC
### Compatibility Issues
Power Adapter Compatibility
- Requires adapters with proper identification (PSEL/ACDRV)
- May need additional circuitry for third-party adapters
Battery Pack Integration
- Must match battery management system (BMS) communication protocol
- Requires compatible battery authentication circuits
System Power Sequencing
- Ensure proper startup sequencing with system processors
- Coordinate with system power management ICs
### PCB Layout Recommendations
Power Path Layout
- Keep high-current paths short and wide (minimum 20 mil width for 5A)
- Place input/output capacitors close to IC pins
- Use separate ground planes for analog and power sections
Thermal Management
- Utilize thermal vias under the QFN package
- Provide adequate copper area for heat dissipation
- Consider external heatsinking for high-power applications
Signal Integrity
- Route sensitive analog signals away from switching nodes
- Use guard rings around critical analog pins
- Implement proper decoupling capacitor placement
## 3. Technical Specifications
### Key Parameter Explanations
Input Voltage Range : 5V to 24V operation
- Supports wide range of AC/DC adapters
- Includes 28V absolute maximum rating for transient protection
Charging Current : Programmable up to 10A
- Set via external resistor and I²C communication
- Supports pre-charge and termination current settings
Battery Voltage : 2-4 series cells (8.4V to 16.8V)
- Configurable for different battery configurations
- Supports various Li-ion chemistries
Switching Frequency :
