bqSWITCHER(TM) Synchronous, Switch-Mode Li-Ion Charger w/ 2-A FET in QFN, 1- or 2-cell, Sys-Controll# BQ24113RHLR Technical Documentation
## 1. Application Scenarios
### Typical Use Cases
The BQ24113RHLR is a highly integrated single-cell Li-ion battery charger and system power path management device designed for space-constrained portable applications. Primary use cases include:
- Smartphones and Tablets : Provides efficient charging while maintaining system operation during high-current consumption scenarios
- Portable Medical Devices : Enables safe battery charging for handheld diagnostic equipment and patient monitoring systems
- Wearable Electronics : Compact solution for smartwatches, fitness trackers, and wireless earbuds
- IoT Devices : Powers connected sensors, smart home controllers, and portable communication equipment
- Portable POS Systems : Supports battery-powered payment terminals and inventory management devices
### Industry Applications
- Consumer Electronics : Mobile phones, digital cameras, portable gaming devices
- Medical Technology : Blood glucose meters, portable oxygen monitors, diagnostic imaging accessories
- Industrial Automation : Handheld scanners, portable test equipment, wireless sensor networks
- Automotive Accessories : Aftermarket car entertainment systems, GPS navigation units
- Telecommunications : Two-way radios, satellite phones, network testing equipment
### Practical Advantages and Limitations
Advantages:
- Integrated Power Path Management : Allows system to operate immediately when connected to power source, even with deeply discharged battery
- High Efficiency Operation : Up to 92% efficiency with 1.5A charge current reduces thermal dissipation
- Compact Package : 3mm × 3mm QFN-20 package saves board space
- Flexible Input Source : Supports 4.35V to 6.4V input range from USB or adapter
- Safety Features : Includes thermal regulation, input current optimization, and battery temperature monitoring
Limitations:
- Single-Cell Only : Limited to 4.2V/4.35V battery configurations
- Maximum Charge Current : 1.5A may be insufficient for high-capacity battery applications
- Thermal Constraints : High current charging requires proper thermal management in compact designs
- Input Voltage Range : Not compatible with higher voltage adapters beyond 6.4V
## 2. Design Considerations
### Common Design Pitfalls and Solutions
Pitfall 1: Inadequate Thermal Management
- Problem : Overheating during high-current charging reduces efficiency and may trigger thermal shutdown
- Solution : Implement proper thermal vias under the package, use copper pours for heat dissipation, and consider airflow in enclosure design
Pitfall 2: Input Source Instability
- Problem : Unstable input voltage from poor quality adapters causing charging interruptions
- Solution : Add input capacitance (10μF ceramic + 1μF ceramic close to IC) and implement input overvoltage protection
Pitfall 3: Battery Connection Issues
- Problem : Poor battery contact or long traces causing voltage sensing inaccuracies
- Solution : Route battery sense lines directly to connector, use Kelvin connections for accurate voltage measurement
Pitfall 4: Incorrect Component Selection
- Problem : Wrong inductor values or poor quality capacitors affecting performance
- Solution : Use recommended 1μH to 2.2μH inductor with low DCR and high saturation current rating
### Compatibility Issues with Other Components
Power Management Integration:
- DC/DC Converters : Ensure proper sequencing when multiple power rails are present
- Fuel Gauges : Compatible with most battery fuel gauge ICs via I²C communication
- USB Controllers : Works with USB PD controllers but requires additional negotiation circuitry
Microcontroller Interfaces:
- I²C Communication : Standard 400kHz I²C interface compatible with most microcontrollers
- GPIO Integration : STAT and PG outputs can directly
