Host-Controlled Synchronous Swithc-Mode Li-Ion Charger w/2A FET, 1 or 2 Cell 20-VQFN -40 to 85# BQ24113ARHLR Technical Documentation
Manufacturer : Texas Instruments (TI)
## 1. Application Scenarios
### Typical Use Cases
The BQ24113ARHLR is a highly integrated single-cell Li-ion and Li-polymer battery charger IC designed for space-constrained portable applications. Key use cases include:
- Smartphones and Tablets : Provides complete charging solution with 1.5A maximum charge current
- Portable Medical Devices : Offers precise charge termination and thermal regulation for safety-critical applications
- Wearable Electronics : Small 3mm × 3mm QFN package ideal for compact designs
- Bluetooth Headsets and IoT Devices : Supports charging from USB ports or AC adapters
- Digital Cameras and Portable Media Players : Handles various input sources with automatic detection
### Industry Applications
- Consumer Electronics : Mobile devices, smart watches, fitness trackers
- Medical Technology : Portable monitors, diagnostic equipment
- Industrial Equipment : Handheld scanners, data collection devices
- Automotive Accessories : In-car charging systems, portable navigation
- Aerospace : Portable test equipment, handheld communication devices
### Practical Advantages and Limitations
Advantages:
- High integration reduces external component count (only 4 external components required)
- Wide input voltage range: 4.35V to 6.45V
- Programmable charge current up to 1.5A
- Thermal regulation protects device during high-power operation
- 28V input overvoltage protection
- Automatic power source detection (USB or adapter)
Limitations:
- Single-cell Li-ion/Li-polymer only (not suitable for multi-cell configurations)
- Maximum charge current of 1.5A may be insufficient for high-capacity batteries
- Requires careful thermal management in high-ambient-temperature environments
- No support for newer battery chemistries like LiFePO4
## 2. Design Considerations
### Common Design Pitfalls and Solutions
Pitfall 1: Inadequate Thermal Management
- Issue : Overheating during high-current charging
- Solution : Ensure proper thermal vias under the package and adequate copper area for heat dissipation
Pitfall 2: Input Voltage Transients
- Issue : Damage from voltage spikes exceeding absolute maximum ratings
- Solution : Implement input TVS diode and ensure input capacitor is placed close to VIN and GND pins
Pitfall 3: Battery Connection Issues
- Issue : Intermittent battery connection causing charge termination errors
- Solution : Use battery connector with secure mechanical retention and implement proper debouncing circuitry
### Compatibility Issues with Other Components
Microcontroller Interface:
- I²C compatible but requires pull-up resistors (1kΩ to 10kΩ recommended)
- Ensure microcontroller I/O voltage levels are compatible with BQ24113 logic levels
Battery Protection:
- Works well with standard battery protection circuits
- Ensure battery NTC thermistor meets specifications (typically 10kΩ NTC with β = 3380K)
Power Management ICs:
- Compatible with most PMICs but requires careful sequencing during power-up
- May conflict with other charging circuits if not properly disabled
### PCB Layout Recommendations
Power Path Layout:
- Place input capacitor (C1) within 2mm of VIN and GND pins
- Use wide traces for BAT, SYS, and VIN paths (minimum 20 mil width for 1A current)
- Keep high-current paths short and direct
Thermal Management:
- Use thermal vias in the exposed thermal pad (connect to ground plane)
- Provide adequate copper area around the device for heat spreading
- Consider using additional ground planes on inner layers
Signal Integrity:
- Route I²C signals (SDA
