EUP8207-4.2/8.4/8.4A Switch Mode Li-Ion/Polymer Battery Charger DESCRIPTION FEATURES The EUP8207 is a constant current, constant voltage Li-Ion battery charger controller that uses a current mode PWM step-down (buck) switching architecture. With a 500kHz switching frequency, the EUP8207 provides a small, simple and efficient solution to fast charge one (4.2V) or two (8.4V) cell lithium-ion batteries. Wide Input Supply Voltage Range: 4.8V to 20V – 4.2 Version 8.9V to 20V – 8.4 Version 8.9V to 20V – 8.4A Version 500kHz Switching Frequency End-of-Charge Current Detection Output 7 Hour Charge Termination Timer ±1% Charge Voltage Accuracy ±10% Charge Current Accuracy Low 10µA Reverse Battery Drain Current Automatic Battery Recharge Automatic Trickle Charging of Low Voltage Batteries Automatic Sleep Mode for Low Power Consumption Battery Temperature Sensing Stable with Ceramic Output Capacitor 8-Lead SOP and 10-Lead TDFN Packages RoHS Compliant and 100% Lead (Pb)-Free The EUP8207 charges the battery in three phases: conditioning, constant current, and constant voltage. An external sense resistor sets the charge current with ±10% accuracy. An internal resistor divider and precision reference set the final float voltage to 4.2V per cell with ± 1% accuracy. An internal comparator detects the near end-of-charge condition while an internal timer sets the total charge time and terminates the charge cycle. The EUP8207 automatically re-starts the charge if the battery voltage falls below an internal threshold, 4.05V per cell. The EUP8207 also automatically enters sleep mode when DC supplies are removed. The EUP8207 is available in the 8-lead SOP and 10-lead TDFN packages. APPLICATIONS Typical Operating Performance Small Notebook Computer Portable DVD Handheld Instruments Efficiency vs Input voltage Efficiency vs Input voltage 100 100 (Curves include input diode) 95 90 90 EFFICIENCY(%) EFFICIENCY(%) (Curves include input diode) 95 85 80 75 70 75 EUP8207-4.2 VBAT=3.8V VBAT=4.0V 65 60 60 8 10 12 14 16 18 5 20 Ver 1.1 May 2011 10 15 Input Voltage (V) Input Voltage (V) DS8207 80 70 EUP8207-8.4 VBAT=7.0V VBAT=8.0V 65 85 1 20 EUP8207-4.2/8.4/8.4A Typical Application Circuit Figure 1. 1.5A Single Cell/2.0A Dual Cells Li-Ion Battery Charger DS8207 Ver 1.1 May 2011 2