bqSWITCHER(TM) Synchronous, Switch-Mode Li-Ion Charger w/ 2-A FET in QFN, 1- or 2-cell, Sys-Controll# BQ24113RHLR Technical Documentation
*Manufacturer: Texas Instruments (BB/TI)*
## 1. Application Scenarios
### Typical Use Cases
The BQ24113RHLR is a highly integrated single-cell Li-ion and Li-polymer battery charger IC designed for space-constrained portable applications. Primary use cases include:
- Smartphones and Tablets : Provides complete charging solution for modern mobile devices with USB compatibility
- Portable Medical Devices : Enables safe charging for medical monitoring equipment and portable diagnostic tools
- Wearable Electronics : Compact form factor ideal for smartwatches, fitness trackers, and health monitors
- Portable Audio Equipment : Powers wireless headphones, Bluetooth speakers, and portable audio players
- IoT Devices : Suitable for battery-powered sensors, smart home devices, and connected peripherals
### Industry Applications
- Consumer Electronics : Mobile computing, personal entertainment systems
- Medical Technology : Patient monitoring devices, portable diagnostic equipment
- Industrial IoT : Remote sensors, data loggers, portable test equipment
- Automotive Accessories : Aftermarket car electronics, portable navigation devices
### Practical Advantages and Limitations
Advantages:
- High Integration : Combines power MOSFETs, current sensing, and reverse-blocking protection in single package
- USB-OTG Support : Can operate in boost mode to power USB peripherals (5V/500mA)
- Thermal Regulation : Automatic charge current reduction during high temperature conditions
- Small Footprint : 3mm × 3mm QFN package ideal for space-constrained designs
- High Efficiency : Up to 92% efficiency with 1.5A charge current capability
Limitations:
- Single-Cell Only : Limited to 4.2V/4.35V battery configurations
- Current Limitation : Maximum 1.5A charge current may be insufficient for high-capacity batteries
- Input Voltage Range : 3.9V to 6.2V input range restricts some high-voltage applications
- Thermal Constraints : May require thermal management in high-ambient temperature environments
## 2. Design Considerations
### Common Design Pitfalls and Solutions
Pitfall 1: Inadequate Thermal Management
- Problem : Overheating during high-current charging leading to thermal shutdown
- Solution : Ensure proper thermal vias under package, adequate copper area for heat dissipation
Pitfall 2: Input Voltage Transients
- Problem : Damage from voltage spikes on USB/VBUS input
- Solution : Implement TVS diodes and input capacitors close to IC pins
Pitfall 3: Battery Detection Issues
- Problem : False battery detection or premature termination
- Solution : Proper battery sense resistor selection and Kelvin connection implementation
Pitfall 4: Ground Bounce
- Problem : Noise affecting charge termination accuracy
- Solution : Use star grounding technique and separate analog/digital grounds
### Compatibility Issues with Other Components
Power Management Integration:
- DC-DC Converters : Ensure proper sequencing with system power rails
- Fuel Gauges : Compatible with most battery fuel gauge ICs via I²C communication
- USB Controllers : Requires proper USB detection circuitry for input current limiting
Microcontroller Interface:
- I²C compatible (400kHz) with standard microcontrollers
- Requires pull-up resistors on SCL/SDA lines (typically 10kΩ)
- GPIO interfaces for status monitoring and control
### PCB Layout Recommendations
Power Path Layout:
- Place input capacitors (10μF ceramic) within 2mm of VBUS and PGND pins
- Battery connection capacitors (10μF) should be positioned close to BAT pin
- Use wide traces for high-current paths (minimum 20 mil
