TP4054

TP4054 is a constant-current/constant-voltage linear charger IC primarily designed for single-cell lithium battery charging. No external sense resistor is required, and its internal MOSFET architecture eliminates the need for an external blocking diode. Under high power dissipation or elevated ambient temperature conditions, the TP4054 automatically reduces the charge current to limit the die temperature. The charge voltage is fixed at 4.2V, and the charge current is adjustable via a single external resistor. When the float voltage is reached and the charge current drops to 1/10 of the programmed value, the TP4054 automatically terminates the charge cycle. Once the input voltage is removed, the TP4054 enters a low-current state, drawing less than 2µA from the battery. In standby mode, the supply current is less than 25µA. The TP4054 also monitors charge current and features undervoltage lockout, automatic recharge, and a status pin that indicates both charge termination status and input voltage presence.

Applications

• Mobile phones
• PDAs
• MP3 players
• Bluetooth headsets

Key features

• Programmable charge current up to 500mA
• No external MOSFET, sense resistor, or reverse diode required
• Constant current/constant voltage operation with thermal protection
• Li-ion battery charging via USB port
• Preset charge voltage with 1% accuracy
• 20uA standby current
• 2.9V trickle charge voltage
• Soft-start limits inrush current
• SOT23-5 package