• Power Up System without Battery
• Charge Faster than Linear Chargers
• High-Accuracy Voltage and Current Regulation
  • Input Current Regulation Accuracy: ±5% (100 mA and 500 mA)
  • Charge Voltage Regulation Accuracy: ±0.5% (25°C), ±1% (0°C to 125°C)
  • Charge Current Regulation Accuracy: ±5%
• Input Voltage Based Dynamic Power Management (VIN DPM)
• Bad Adaptor Detection and Rejection
• Safety Limit Register for Maximum Charge Voltage and Current Limiting
• High-Efficiency Mini-USB/AC Battery Charger for Single-Cell Li-Ion and Li-Polymer Battery Packs
• 20-V Absolute Maximum Input Voltage Rating
• 6.5-V Maximum Operating Input Voltage
• Built-In Input Current Sensing and Limiting
• Integrated Power FETs for Up To 1.55-A Charge Rate
• Programmable Charge Parameters through I2C™ Compatible Interface (up to 3.4 Mbps):
  • Input Current Limit
  • VIN DPM Threshold
  • Fast-Charge/Termination Current
  • Charge Regulation Voltage (3.5 V to 4.44 V)
  • Low Charge Current Mode Enable/Disable
  • Termination Enable/Disable
• Support up to 1.55A Charge Current using 55 mΩ Sensing Resistor
• Synchronous Fixed-Frequency PWM Controller Operating at 3 MHz With 0% to 99.5% Duty Cycle
• Automatic High Impedance Mode for Low Power Consumption
• Robust Protection
  • Reverse Leakage Protection Prevents Battery Drainage
  • Thermal Regulation and Protection
  • Input/Output Overvoltage Protection
• Status Output for Charging and Faults
• USB Friendly Boot-Up Sequence
• Automatic Charging
• Boost Mode Operation for USB OTG
  • Input Voltage Range (from Battery): 3.2 V to 4.5 V
• 2.1 mm x 2 mm 20-Pin WCSP Package

• Mobile and Smart Phones
• MP3 Players
• Handheld Devices

The bq24157 is a compact, flexible, high-efficiency, USB-friendly switch-mode charge management device for single-cell Li-ion and Li-polymer batteries used in a wide range of portable applications. The charge parameters can be programmed through an I2C interface. The IC integrates a synchronous PWM controller, power MOSFETs, input current sensing, high-accuracy current and voltage regulation, and charge termination, into a small WCSP package.