USB compatible single-cell lithium-ion battery charger circuit diagram

bq24153A/6A/8/9 Fully Integrated Switch Mode Single Cell Li-Ion Battery Charger is a compact, flexible, high efficiency, friendly USB switch mode charge management device with single-cell Li-ion battery, lithium polymer battery, widely used Portable application. The charging parameters can be programmed via the I2C interface. The IC integrates a synchronous PWM controller, power MOSFET trumpet, input current sensing, high precision current and voltage regulation, and charge termination to become a small WCSP package.

The IC charges the battery in three phases: regulation, constant current, and constant voltage. The set value of the input current is automatically limited by the host. Charging termination is based on the battery voltage and the user selectable minimum current level. The safety timer for reset control, the I2C interface provides a secure backup. During normal operation, the IC automatically restarts the charge cycle. If the battery voltage drops below the internal threshold and automatically enters sleep mode or high impedance mode, the input power is removed. The chargeable status is reported to the I2C interface used by the host. During the charging process, the IC monitors its junction temperature (TJ), reducing the charging current once TJ increases to approximately 125 °C. Supporting USB OTG devices, the bq24153A / 8 can provide VBUS by increasing the battery voltage (5.05V). Available in a 20-pin WCSP packaged IC.

Features • Faster charging than linear chargers • High precision voltage and current regulation • Input current regulation accuracy: ±5% (100 mA and 500 mA)
• Charging voltage adjustment accuracy: ±0.5% (25°C), ±1%
• (0°C to 125°C)
• Charging current adjustment accuracy: ± 5%