TP4057 IC – 4.2V – Lithium Ion Battery Charger – SOT-23-6

The TP4057 IC is a complete single-cell Li-ion battery charger with reverse battery polarity protection and constant current constant voltage linear control. Its SOT package and low external component count make the TP4057 ideal for portable applications. TP4057 IC can work with USB power and adapter power. Thermal feedback automatically adjusts the charge current to limit the die temperature during high power operation or high ambient temperature conditions. The full voltage is fixed at 4.2V, while the charge current can be set externally with a resistor. When the battery reaches 4.2V , the charging current drops to 1/10 of the set value, and the TP4057 will automatically terminate the charging.

When the input voltage (AC adapter or USB power supply) is removed, the TP4057 automatically enters a low current state and the battery leakage current is below 2uA . Other features of the TP4057 IC include a charge current monitor, undervoltage lockout, automatic recharge, and two status pins to indicate end of charge and input voltage engagement.

Features:

• Li-ion battery reverse polarity protection
• Programmable charge current up to 500mA
• No MOSFET, sense resistor or blocking diode required
• Preset charge voltage of 4.2V with ±1% accuracy
• Input Power Supply Voltage (VCC): -0.3V to 9V
• C/10 charge termination
• Charge single-cell Li-Ion battery directly from USB port;
• Supply current in standby mode is 40uA