ADP2105

Data Sheet FEATURES Extremely high 97% efficiency Ultralow quiescent current: 20 μA 1.2 MHz switching frequency 0.1 μA shutdown supply current Maximum load current ADP2105: 1 A ADP2106: 1.5 A ADP2107: 2 A Input voltage: 2.7 V to 5.5 V Output voltage: 0.8 V to VIN Maximum duty cycle: 100% Smoothly transitions into low dropout (LDO) mode Internal synchronous rectifier Small 16-lead 4 mm × 4 mm LFCSP package Optimized for small ceramic output capacitors Enable/shutdown logic input Undervoltage lockout Soft start Supported by ADIsimPower™ design tool APPLICATIONS Mobile handsets PDAs and palmtop computers Telecommunication/networking equipment Set top boxes Audio/video consumer electronics TYPICAL OPERATING CIRCUIT 0.1μF 10Ω VIN INPUT VOLTAGE = 2.7V TO 5.5V 10μF FB ON OFF 16 FB 1 EN 15 GND 14 13 IN PWIN1 LX2 12 OUTPUT VOLTAGE = 2.5V 2 GND PGND 11 ADP2107-ADJ 3 GND LX1 10 4 GND VIN PWIN2 9 2μH 85kΩ FB 40kΩ COMP SS AGND NC 5 6 7 8 10μF 10μF 4.7μF LOAD 0A TO 2A 1nF 70kΩ 120pF NC = NO CONNECT Figure 1. Circuit Configuration of ADP2107 with VOUT = 2.5 V 06079-002 1 A/1.5 A/2 A Synchronous, Step-Down DC-to-DC Converters ADP2105/ADP2106/ADP2107 GENERAL DESCRIPTION The ADP2105/ADP2106/ADP2107 are low quiescent current, synchronous, step-down dc-to-dc converters in a compact 4 mm × 4 mm LFCSP package. At medium to high load currents, these devices use a current mode, constant frequency pulse-width modulation (PWM) control scheme for excellent stability an...