MAX1811 USB-Powered Li+ Charger Pin DescriptionPINNAMEDESCRIPTION 1 SELV Battery Regulation Voltage-Select Input. A low (< 0.8V) selects a 4.1V battery regulation set point. A high (> 2.0V) selects a 4.2V battery regulation set point. Battery Regulation Current-Select Input. A low (< 0.8V) selects a 100mA maximum battery regulation 2 SELI current. A high (> 2.0V) selects a 500mA maximum battery regulation current. SELI is not diode clamped to IN, and the voltage at VSELI can exceed the voltage at VIN. 3, 6 GND Ground. Connect pins 3 and 6 to a large copper trace for maximum power dissipation. 4 IN Input Supply Voltage. Bypass with a 4.7µF capacitor to GND. 5 BATT Li+ Battery Connection. Bypass with a capacitor no less than 2.2µF to GND. High impedance in shutdown. 7 EN Enable Input. A high (> 2.0V) enables the device. A low (< 0.8V) disables the device and places it into shutdown mode. BATT is high impedance when disabled. 8 CHG Charging Indicator Open-Drain Output. CHG pulls low while the device is in charge mode (2.5V < VBATT < BATT Regulation Voltage). SELI IN VOLTAGE CURRENT LOOP SELECTOR REGULATOR BATT THERMAL LOOP 3V CHG VOLTAGE EN BIAS SELECTOR OVERCURRENT 4.7V (2.5V, 4.2V) DETECTOR BATTERY 2V OVERVOLTAGE MAX DETECTOR DETECTOR CIRCUIT CURRENT LOOP MAX1811 CURRENT- SENSE CIRCUIT SELV GND Figure 1. Functional Diagram www.maximintegrated.com Maxim Integrated │ 5