LN4056A

LN4056A is a charger circuit component that performs constant-current/constant-voltage charging for single-cell rechargeable lithium batteries. The device integrates an internal power transistor, eliminating the need for external current-sense resistors and blocking diodes. LN4056A requires minimal external components and complies with the USB bus specification, making it ideal for portable applications. A thermal regulation circuit keeps the die temperature within a safe range when the device dissipates high power or operates in elevated ambient temperatures. The internal constant-voltage charge voltage is fixed at 4.2V and can also be adjusted via an external resistor. Charge current is set by an external resistor. When the input voltage (AC adapter or USB power supply) is removed, LN4056A automatically enters a low-power sleep mode in which battery current consumption is less than 0.1μA. When the battery voltage exceeds the input voltage, the internal power MOSFET is automatically turned off. Additional features include input undervoltage lockout, automatic recharge, battery temperature monitoring, and charge status/charge termination status indication. LN4056A can disable charging via an enable pin; in the shutdown state, quiescent current consumption is below 20uA. LN4056A is available in a thermally enhanced 8-pin small outline package, ESOP8.

Applications

• Mobile phones
• Digital cameras
• MP4 players
• Bluetooth applications
• Electronic dictionaries
• Constant current/constant voltage 4.2V charging applications
• Various chargers for portable devices
• Power banks

Key features

• Programmable charge current up to 1.0A
• No external MOSFET, sense resistors, or blocking diodes required
• Small form factor for complete linear charge management of Li-ion batteries
• Constant-current/constant-voltage operation with thermal regulation for maximum charge efficiency without risk of overheating
• Single-cell Li-ion battery management via USB interface
• Charge current output monitoring
• Charge status indicator and charge complete status flag
• 1/10 charge current termination
• Automatic recharge
• 40μA supply current in shutdown mode
• 2.9V trickle charge threshold voltage
• Soft-start to limit inrush current
• Zero battery drain from IC when VIN is removed
• Available in ESOP8 and custom package options