IDCHIP AD4054

The AD4054 is a complete single-cell lithium-ion battery CC/CV linear charger. Housed in a tiny SOT-23-5 package with minimal external components, the AD4054 is ideally suited for portable applications. The AD4054 is compatible with USB power supplies and adapter power sources.

The internal PMOSFET architecture, combined with an anti-reverse charging circuit, eliminates the need for an external isolation diode. Thermal feedback automatically adjusts the charge current to limit die temperature during high-power operation or elevated ambient temperature conditions. The charge voltage is fixed at 4.2V, while the charge current is externally programmable via a single resistor. When the charge current drops to 1/10 of the programmed value after reaching the final float voltage, the AD4054 automatically terminates the charge cycle.

When the input voltage (AC adapter or USB power supply) is removed, the AD4054 automatically enters a low-current state, reducing battery leakage current to below 2uA. The AD4054 can also be placed into shutdown mode while power is applied, reducing supply current to 25uA. Additional features of the AD4054 include battery temperature monitoring, undervoltage lockout, automatic recharge, and two LED status pins for end-of-charge indication.

• Programmable charge current up to 600mA
• No MOSFET, sense resistor, or blocking diode required
• Complete linear charger for single-cell Li-Ion batteries in SOP package
• Constant-current/constant-voltage operation with thermal regulation for maximizing charge rate without risk of overheating
• 4.2V preset charge voltage with ±1% accuracy
• Charge current monitor output for battery fuel gauging
• Automatic recharge
• C/10 charge termination with LED indicator off
• 2.9V trickle charge device version
• Soft-start limits inrush current
• Battery temperature monitoring
• 25uA supply current in standby mode
• No overvoltage protection

• Mobile phones
• PDA
• MP3, MP4 players
• Bluetooth headsets
• Bluetooth speakers
• Digital cameras
• Electronic dictionaries
• GPS
• Portable devices
• Various chargers