Suntek SK4555D8-42

The SK4555 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 end-of-charge (EOC) current are programmable with external resistors. When the battery voltage is lower than 2.55V, the charger preconditions the battery with typically 20% of the programmed charge current. When the charge current reduces to the programmable EoC current level during the CV charge phase, the charging process is terminated, and meanwhile an EOC 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 1uA leakage current from the battery. The SK4555 is available in Green DFN-2x2-8L packages and is rated between -40°C to +85°C temperature range.

• 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 End-of-Charger Current
• Charge termination when charge current reduces to EOC Current
• Charger Current Thermal Foldback for Thermal Protection
• 2.55V Trickle Charge Threshold
• 6.8V Input Over-Voltage Protection
• 24V Maximum Voltage for the Power Input
• Power Presence and Charge Indications
• Less than 1uA Leakage Current from the Battery When No Input Power Attached
• Less than 200uA Supply Current when Charging is terminated
• Available in Green DFN-2x2-8L Packages

• Mobile Phones
• Blue-Tooth Devices
• PDAs
• MP3 Players
• Stand-Alone Chargers
• Other Handheld Devices