GN4054B

GN4054B is a complete single-cell lithium-ion battery CC/CV linear charger. Its SOT package and minimal external component count make the GN4054B an ideal choice for portable applications. The GN4054B is compatible with both USB power supplies and adapter power supplies. Due to the internal PMOSFET architecture and reverse-charge protection circuitry, no external sense resistors or isolation diodes are required. Thermal feedback regulates the charge current to limit the die temperature during high-power operation or elevated ambient temperature conditions. The charge voltage is fixed at 4.2V, while the charge current can be externally programmed via a single resistor. When the charge current drops to 1/10 of the programmed value after reaching the final float voltage, the GN4054B automatically terminates the charge cycle. When the input voltage (AC adapter or USB power supply) is removed, the GN4054B automatically enters a low-current state, reducing battery leakage current to below 2uA. The GN4054B can also be placed into shutdown mode, reducing supply current to 50uA. Additional features of the GN4054B include charge current monitoring, UVLO, automatic recharge, and a status pin for indicating charge termination and input voltage presence.

Applications

• Lithium battery charger

Key features

• Programmable charge current up to 500mA
• No MOSFET, sense resistor, or isolation diode required
• Complete linear charger for single-cell Li-Ion batteries in SOT23-5 package
• Constant current/constant voltage operation with thermal regulation
• Direct Li-Ion battery charging from USB port
• 4.2V preset charge voltage
• C/10 charge termination; automatic recharge
• Charge status output pin
• 50uA supply current in standby mode
• 2.9V trickle charge device version