GENERAL DESCRIPTION
The PW4554 is a cost-effective, fully integrated high input voltage single-cell Li-ion battery charger. The charger uses a CC/CV charge profile required by Li-ion battery. The charger accepts an input voltage up to 24V but is disabled when the input voltage exceeds the OVP threshold, typically 6.8V, to prevent excessive power dissipation. The 24V rating eliminates the over-voltage protection circuit required in a low input voltage charger.
The charge current and the Full-of-charge (FOC) current are programmable with external resistors.
When the battery voltage is lower than 2.55V, the charger preconditi*** the battery with typically 20% of the programmed charge current. When the charge current reduces to the programmable FOC current level during the CV charge phase, an FOC indication is provided by the CHG pin,which is an open-drain output. An internal thermal foldback function protects the charger from any thermal failure. Two indication pins (PPR and CHG) allow simple interface to a microprocessor or LEDs. When no adapter attached, the charger draws less than 1μA leakage current from the battery.
The PW4554 is ***ailable in Green DFN-2×2-8L packages and is rated between -40 ℃ to +85 ℃ temperature range.
FEATURES
- Complete Charger for Single-Cell-Li-ion or Polymer Batteries
- Integrated Pass Element and Current Sensor
- No External Blocking Diode Required
- Low Component Count and Cost
- Programmable Charger Current
- Programmable Full-of-Charger Current
- Charger Current Thermal Foldback for Thermal Protection