Li-Ion Linear (8.2V & 8.4V) Charge Management IC For Two-Cell Apps W/Integrated FET, Bi-Color LED# BQ24006 Single-Chip Li-Ion and Li-Pol Charger IC Technical Documentation
*Manufacturer: Texas Instruments (TI)*
## 1. Application Scenarios
### Typical Use Cases
The BQ24006 is a highly integrated single-chip Li-Ion and Li-Polymer battery charger IC designed for space-constrained portable applications. Key use cases include:
- Portable Medical Devices : Insulin pumps, portable monitors, and diagnostic equipment requiring reliable battery charging with thermal protection
- Consumer Electronics : Smartphones, tablets, digital cameras, and portable media players
- Industrial Handhelds : Barcode scanners, portable data terminals, and measurement instruments
- Wearable Technology : Smartwatches, fitness trackers, and medical monitoring devices
- IoT Devices : Wireless sensors, smart home controllers, and portable communication equipment
### Industry Applications
- Healthcare : Medical devices requiring precise charging control and safety features
- Consumer Electronics : Mass-market portable devices needing cost-effective charging solutions
- Industrial Automation : Rugged devices operating in varying environmental conditions
- Telecommunications : Mobile communication equipment requiring efficient power management
- Automotive Accessories : Aftermarket car kits and portable navigation systems
### Practical Advantages and Limitations
Advantages:
- High Integration : Combines power FET, current sensor, and reverse-blocking protection in single package
- Thermal Regulation : Automatically reduces charge current to control die temperature
- Compact Solution : Requires minimal external components (typically 4-5 passive components)
- Safety Features : Includes battery temperature monitoring, charge timeout, and reverse polarity protection
- Flexible Power Sources : Supports both USB and wall adapter inputs with automatic detection
Limitations:
- Fixed Charge Voltage : Limited to 4.2V ±1% for single-cell Li-Ion/Li-Pol batteries
- Maximum Current : 800mA maximum charge current may be insufficient for high-capacity batteries
- Temperature Range : Operating range of 0°C to 125°C may not suit extreme environment applications
- Package Constraints : QFN-10 package requires careful PCB design and manufacturing expertise
## 2. Design Considerations
### Common Design Pitfalls and Solutions
Pitfall 1: Inadequate Thermal Management
- Problem : Excessive heating leading to thermal shutdown or reduced charge current
- Solution : Ensure proper PCB thermal vias under exposed pad, use adequate copper area for heat dissipation
Pitfall 2: Input Voltage Instability
- Problem : Fluctuating input voltage causing charging interruptions
- Solution : Implement proper input capacitance (10μF recommended) and consider input voltage supervisor circuit
Pitfall 3: Battery Connection Issues
- Problem : Intermittent battery connections triggering false charge termination
- Solution : Use robust battery connectors and implement proper debouncing circuits
Pitfall 4: ESD Vulnerability
- Problem : Static discharge damaging sensitive charger circuitry
- Solution : Incorporate ESD protection diodes on input and output lines
### Compatibility Issues with Other Components
Power Management Integration:
- DC-DC Converters : Ensure proper sequencing when used with system power management ICs
- Microcontrollers : Compatible with most MCUs through standard GPIO control interface
- Fuel Gauges : Works well with TI's battery fuel gauge ICs (bq series) for comprehensive battery management
- USB Controllers : May require level shifting for 5V-tolerant I/O when interfacing with 3.3V systems
Component Selection Guidelines:
- Input Capacitor : 10μF ceramic capacitor (X5R or X7R dielectric) recommended
- Output Capacitor : 10μF ceramic capacitor for stable operation
- Battery Temperature Sensor : 10kΩ
