UMW TP4057

TP4057 is a high-performance single-cell lithium-ion battery constant-current/constant-voltage linear charger. It comes in a SOT23-6 package with minimal external components, making it ideal for portable products and suitable for both USB and adapter power supplies. Based on a special internal MOSFET architecture and reverse-charge protection circuit, TP4057 requires no external sense resistors or isolation diodes. A thermal feedback function regulates the charging current to reduce die temperature when the ambient temperature is too high or during high-power applications. The charge voltage is fixed at 4.24V, while the charge current is programmable via an external resistor. When the charge current drops to 1/10 of the programmed value after reaching the final float voltage, the chip terminates the charge cycle. When the input power is disconnected, TP4057 enters sleep mode and the battery leakage current drops below 1μA. TP4057 can be configured in shutdown mode, reducing the quiescent current to 25μA. TP4057 also includes additional features: battery temperature monitoring, undervoltage lockout, automatic recharge, and two status pins for indicating charge and charge termination states.

• Programmable charge current up to 500mA
• No external MOSFET, sense resistor, or blocking diode required
• Complete single-cell Li-Ion linear charger in SOT23-6 package
• Constant-current/constant-voltage operation with thermal regulation to maximize charge rate without risk of overheating
• Preset charge voltage accuracy of 4.24V, ±1% accuracy
• Charge current monitor output for battery fuel gauging
• Automatic recharge
• Dual charge status, battery absent, and fault status indicator outputs
• C/10 charge termination
• 25μA quiescent current in standby mode
• 2.9V trickle charge
• Soft-start current limiting

• Mobile phones
• PDA
• MP3 and MP4 players
• Chargers
• Digital cameras