MAX1811 USB-Powered Li+ Charger Charging from AC AdaptersCapacitor Selection The MAX1811 also operates from sources other than Use a minimum of 2.2µF placed close to BATT for proper USB ports. The full charging input voltage range is 4.35V stability. Bypass IN to GND with a 4.7µF capacitor. Use to 6.5V. When charging in the 500mA mode with an AC a larger input bypass capacitor for high input voltages or adapter, rely on the thermal loop to limit the power dissipa- high charging current to reduce supply noise. tion by limiting the charge current at higher input voltages if limited PC board area is available to dissipate heat. HOST OR BUS-POWERED LOW-POWER POWERED HUB HUB FUNCTION 4.375V 4.750V 4.735V 4.640V 4.625V *4.400V 4.397V 4.378V 4.500V 4.350V 0.015V 0.000V 0.110V 0.125V 0.000V 0.003V 0.002V 0.025V REFERENCED REFERENCED TO SOURCE TO HUB *UNDER TRANSIENT CONDITIONS, SUPPLY AT HUB CAN DROP FROM 4.00V TO 4.070V. Figure 3. USB Voltage Specification TO LOAD Chip Information BATT 4.35V TO 6.5V IN SINGLE TRANSISTOR COUNT: 1907 Li+ 4.2V CELL PROCESS: BiCMOS SELV 4.1V MAX1811 TO IN ON LED OFF EN Package Information 500mA CHG For the latest package outline information and land patterns 100mA SELI GND CHG GND LOGIC OUT (footprints), go to www.maximintegrated.com/packages . Note 10kΩ that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. PACKAGEPACKAGEOUTLINELAND Figure 4. Charging from a USB Port TYPECODENO.PATTERN NO. 8 SO S8+6F 21-004190-0096 www.maximintegrated.com Maxim Integrated │ 7