1A, Single-Input, Single-Cell Li-Ion Battery Charger with Operation Over JEITA and 10k? NTC 10-MSOP-PowerPAD -40 to 150# BQ24092DGQR Technical Documentation
## 1. Application Scenarios
### Typical Use Cases
The BQ24092DGQR is a highly integrated single-cell Li-ion battery charger and system power path management device designed for space-constrained portable applications. Key use cases include:
Portable Medical Devices
- Wearable health monitors requiring continuous operation
- Portable diagnostic equipment with battery backup
- Medical sensors needing precise charging control
- Infusion pumps requiring reliable power management
Consumer Electronics
- Smartphones and tablets with USB charging capability
- Wireless earbuds and hearables
- Smart watches and fitness trackers
- Portable gaming devices
Industrial Applications
- Handheld scanners and data collection terminals
- Portable test and measurement equipment
- IoT edge devices with battery backup
- Remote monitoring sensors
### Industry Applications
Healthcare Sector
- Patient monitoring systems requiring 24/7 operation
- Portable diagnostic equipment with strict safety requirements
- Medical wearables needing compact power solutions
Consumer Electronics
- Mobile devices requiring fast charging capabilities
- Wearable technology with limited PCB space
- Smart home devices with battery backup
Industrial & IoT
- Asset tracking devices
- Industrial handheld terminals
- Remote sensor networks
- Field service equipment
### Practical Advantages
Key Benefits:
- Integrated Power Path Management : Allows system operation from battery or external power
- Compact Solution : 3mm × 3mm QFN package saves board space
- High Efficiency : Up to 92% charging efficiency reduces thermal concerns
- Flexible Input Sources : Supports USB and adapter inputs (4.35V to 6.5V)
- Safety Features : Thermal regulation, timer safety, and voltage monitoring
Limitations:
- Single-Cell Only : Limited to 4.2V/4.35V Li-ion/Li-polymer batteries
- Current Limitation : Maximum 1.5A charge current may be insufficient for high-capacity batteries
- Temperature Constraints : Requires proper thermal management at high currents
- Input Voltage Range : Limited to 6.5V maximum, restricting some adapter options
## 2. Design Considerations
### Common Design Pitfalls and Solutions
Thermal Management Issues
- Problem : Inadequate heat dissipation causing thermal shutdown
- Solution : Use thermal vias under package, ensure adequate copper area
- Implementation : Minimum 2oz copper, thermal relief patterns
Input Capacitor Selection
- Problem : Insufficient input capacitance causing voltage droop
- Solution : Use low-ESR ceramic capacitors close to VIN pin
- Implementation : 10μF X5R/X7R ceramic capacitor within 2mm of VIN
Battery Connection Problems
- Problem : Voltage sensing errors due to trace resistance
- Solution : Kelvin connection for battery sense lines
- Implementation : Separate battery voltage sense traces to BAT pin
### Compatibility Issues
Microcontroller Interfaces
- Compatible : I²C-compatible microcontrollers for charge parameter programming
- Considerations : Ensure proper pull-up resistors and signal integrity
Power Management ICs
- Integration : Works well with TI's TPS series DC-DC converters
- Timing : Ensure proper power-up sequencing with system loads
USB Controllers
- Compliance : Meets USB-IF battery charging specification 1.2
- Detection : Automatic detection of USB SDP, CDP, and DCP ports
### PCB Layout Recommendations
Power Path Layout
- Keep input capacitors (C1, C2) within 2mm of VIN and GND pins
- Use wide traces for BAT (≥20 mil) and SYS (≥20 mil) connections
- Separate power and signal grounds, single-point connection
Thermal Management
