NATLINEAR XT4077Y2ASR-G

XT4077 is a charger circuit component capable of performing 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. XT4077 requires minimal external components and complies with the USB bus specification, making it ideal for portable applications.

A thermal regulation circuit controls the chip temperature within a safe range when device power dissipation is high or ambient temperature is elevated. The internal fixed constant-voltage charge voltage is 4.2V, which can also be adjusted via an external resistor. Charge current is set through an external resistor. When the input voltage (AC adapter or USB power supply) is removed, XT4077 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. XT4077 can be disabled via an enable pin; in shutdown mode, the quiescent current consumption is below 20uA.

XT4077 is available in a thermally enhanced 8-pin small outline package ESOP8.

• 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

• 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