WB4054A

A highly integrated, cost-effective single-cell lithium-ion battery charger. Using constant current/constant voltage linear control with minimal external components, making it ideal for portable applications; also compatible with USB power supply and adapter power supply operation. The internal PMOSFET architecture combined with reverse-charge protection eliminates the need for external sense resistors and isolation diodes. Thermal feedback automatically regulates the charge current to limit die temperature during high-power operation or elevated ambient temperature conditions. The full charge voltage is fixed at 4.2V; charge current can be set via an external resistor on the PROG pin, up to 500mA. When the input voltage (AC adapter or USB power supply) is removed, the device automatically enters a low-current state with battery leakage current below 3uA. Additional features include charge current monitor, undervoltage lockout, automatic recharge, and a status pin indicating end-of-charge and input voltage connection. The device is available in a SOT23-5 package.

Applications

• Handheld devices
• Bluetooth devices
• Power tools
• E-cigarettes
• Wearable devices
• Portable devices

Key features

• Standby current < 3 μA
• Battery reverse polarity protection — IC undamaged even if battery is connected in reverse during charging
• ±1% full charge voltage accuracy, termination voltage 4.2V
• 0V battery charging supported
• Automatic recharge