TOP POWER ASIC TP4057-42-SOT26-R

TP4057 is a complete single-cell lithium-ion battery charger with battery polarity reversal protection, employing constant-current/constant-voltage linear control. Its SOT package and minimal external component count make the TP4057 an ideal choice for portable applications. The TP4057 is compatible with both USB power supplies and adapter power supplies.

The internal PMOSFET architecture combined with an anti-backflow charging circuit eliminates the need for external sense resistors and isolation diodes. Thermal feedback automatically adjusts the charge current to limit junction temperature during high-power operation or elevated ambient temperature conditions. The full-charge voltage is fixed at 4.2V, while the charge current can be externally set via a single resistor. When the battery voltage reaches 4.2V, the charge current drops to 1/10 of the programmed value and the TP4057 automatically terminates charging.

When the input voltage (AC adapter or USB power supply) is removed, the TP4057 automatically enters a low-current state with battery leakage current below 2uA. Additional features of the TP4057 include a charge current monitor, undervoltage lockout, automatic recharge, and two status pins for indicating end-of-charge and input voltage connection.

• Li-ion battery reverse polarity protection
• Programmable charge current up to 500mA
• No MOSFET, sense resistor, or blocking diode required
• Single-cell Li-ion CC/CV operation with thermal regulation for maximum charge rate without risk of overheating
• Direct single-cell Li-ion charging from USB port
• 4.2V preset charge voltage with ±1% accuracy
• Input up to 9V
• Automatic recharge
• 2 charge status open-drain output pins
• C/10 charge termination
• 40uA supply current in standby mode
• 2.9V trickle charge device version
• Soft-start to limit inrush current
• 6-pin SOT-23 package

• Charging docks
• Cellular phones, PDAs, MP3 players
• Bluetooth applications