CJ4054A420M

CJ4054 is a complete constant-current/constant-voltage linear charger for single-cell lithium-ion batteries. Its SOT package and minimal external component count make it ideally suited for space-constrained portable applications. In addition, CJ4054 is specifically designed for use in environments compliant with USB power specifications. No external sense resistor is required, and thanks to the internal MOSFET architecture, no blocking diode is needed. Thermal feedback regulates the charge current to limit die temperature during high-power operation or in high-temperature environments. The charge voltage is fixed at VFLOAT, and the charge current can be programmed via a single resistor connected between the PROG pin and ground. Once the final float voltage is reached, CJ4054 automatically terminates the charge cycle when the charge current drops to 1/10 of the programmed value. When the input power source (wall adapter or USB supply) is removed, CJ4054 automatically enters a low-current state, reducing battery drain current to below 2uA. CJ4054 can be placed in shutdown mode, reducing supply current to 25uA. Additional features include charge current monitoring, undervoltage lockout, automatic recharge, and a status pin for indicating charge termination.

Applications

• Cellular Telephones, PDAs, MP3 Players
• Digital Still Cameras Charging Docks and Cradles
• Bluetooth Applications

Key features

• Ideal for Low-Dropout Designs for Single-Cell Li-Ion or Li-Pol Batteries Charge Directly from USB Port or AC Adapter in Space Limited Portable Applications
• Integrated P-ch Power MOSFET and Current Sensor for Up to 800mA Charge Applications
• Reverse Leakage Protection Prevents Battery Drainage
• Pre-charge Conditioning for Reviving Deeply Discharged Cells and Minimizing Heat Dissipation During Initial Stage of Charge
• 2.9V Trickle Charge Threshold
• Constant-Current/Constant-Voltage operation with Thermal Regulation Maximizes Charge Rate Without Risk of Overheating
• Integrated Current and Voltage Regulation ±10% Current Regulation Accuracy ±1% Voltage Regulation Accuracy
• Charge Current Monitor Output for Gas Gauging
• C/10 Charge Termination
• Automatic Recharge
• Status Output for LEDs or System Interface Indicates Charge and Fault Conditions
• Automatic Sleep Mode for Low-Power Consumption
• 25μA Supply Current in Shutdown
• Battery Short-Circuit Protection
• Soft-Start Limits Inrush Current
• Charge Voltage Options: 4.20V and 4.35V