bqTINY-II 1-Cell Li-Ion Charger w/USB/AC Supply Mgmt in 3x3mm2 QFN-10 w/Enable, Timer/Term Enable# BQ24023DRCR Technical Documentation
*Manufacturer: Texas Instruments (BB/TI)*
## 1. Application Scenarios
### Typical Use Cases
The BQ24023DRCR is a highly integrated single-cell Li-ion and Li-polymer battery charger IC designed for space-constrained portable applications. Its primary use cases include:
Portable Medical Devices
- Wearable health monitors (glucose meters, heart rate monitors)
- Portable diagnostic equipment
- Medical patches and sensors
- The device's small package (3mm × 3mm VQFN) and minimal external component count make it ideal for medical wearables requiring reliable battery management
Consumer Electronics
- Smartphones and tablets
- Wireless earbuds and headphones
- Smart watches and fitness trackers
- Digital cameras and portable gaming devices
- USB-powered portable speakers
Industrial IoT Devices
- Wireless sensor nodes
- Asset tracking devices
- Portable data loggers
- Handheld terminals and scanners
### Industry Applications
Healthcare Sector
- Medical monitoring equipment benefits from the IC's precise charge termination and safety features
- Compliance with medical safety standards through integrated protection circuits
- Low quiescent current (typically 15μA) extends battery life in always-on medical devices
Consumer Electronics
- Mass-market consumer products leverage the cost-effective solution
- USB-OTG support enables device functionality while charging peripherals
- Thermal regulation ensures safe operation in compact enclosures
Automotive Accessories
- Aftermarket car accessories (dash cams, GPS units)
- Portable automotive diagnostic tools
- The device operates across the automotive temperature range (-40°C to +85°C)
### Practical Advantages and Limitations
Advantages:
- High Integration : Combines power FETs, current sensor, and reverse blocking protection
- Flexible Input Sources : Supports USB and adapter inputs with automatic detection
- Space Efficiency : 3mm × 3mm package with only 3 external components required
- Safety Compliance : Integrated thermal regulation, charge timer, and battery detection
- Fast Charging : Supports up to 800mA charge current with programmable options
Limitations:
- Single-Cell Only : Limited to 4.2V Li-ion/Li-polymer batteries
- Current Handling : Maximum 800mA charge current may be insufficient for high-capacity batteries
- Thermal Constraints : Power dissipation limits in high-ambient temperature environments
- Input Voltage Range : 4.35V to 6.5V input range may not support all power adapter types
## 2. Design Considerations
### Common Design Pitfalls and Solutions
Input Capacitor Selection
- *Pitfall*: Insufficient input capacitance causing voltage droop during current transients
- *Solution*: Use minimum 10μF ceramic capacitor placed close to IN pin
- *Additional*: Include 1μF high-frequency decoupling capacitor for noise suppression
Thermal Management
- *Pitfall*: Inadequate thermal design leading to premature thermal shutdown
- *Solution*: Ensure proper thermal vias under exposed thermal pad
- *Additional*: Use 2oz copper weight for power traces and thermal relief
Battery Connection Issues
- *Pitfall*: Long battery traces causing voltage sensing inaccuracies
- *Solution*: Route battery sense lines directly to battery connector
- *Additional*: Implement Kelvin connection for accurate voltage measurement
### Compatibility Issues with Other Components
Microcontroller Interfaces
- The STAT and PG outputs are open-drain requiring external pull-up resistors
- Compatible with 1.8V and 3.3V logic levels through appropriate pull-up voltages
- TS input requires careful biasing for temperature monitoring functionality
Power Management Integration
- Conflicts may arise when used with other power path
