FAN4855 Datasheet | Fairchild Semiconductor

Features - Low power PFM boost regulator - Input voltage range is from 1.6V to 4.5V - Output voltage range is from 3V to 5V - 500m A maximum load current capability - 95% efficient power conversion - 2-3 cell and single cell Li-Ion systems - Variable on-time Pulse Frequency Modulation (PFM) - Internal synchronous rectifier (no need for external General Description The FAN4855 is a low power boost regulator designed for low voltage DC to DC conversion in 2-cell battery powered systems such as digital cameras, cell phones and PDAs. The converter starts-up at 1.3V and operates after the start at an input voltage as low as 1V. Output voltage can be adjusted by external resistors from 3.3V to 5V with a maximum load current of 0.5A. Quiescent current in shut-down mode is less than 10µA, which maximizes the battery live time. The ON time changes with the input voltage to maintain the ripple current constant and to provide the highest efficiency over a wide load range- while maintaining low peak currents in the boost inductor. The bination of built-in power transistors, synchronous rectification and low supply current, make the FAN4855 ideal for portable applications. The FAN4855 is available in 8-lead TSSOP package. diode) - Low-battery detection - Logic controlled shutdown with true-load disconnect - Low (80µA) quiescent current - TSSOP-8 Package Applications - DSCs - PDAs - Cell phones, smart phones - Portable instrumentations - 2-3 AA / AAA cells operated devices - Single cell Li-Ion operated devices Ordering Information (TA = -40°C to +85°C) Part Number FAN4855MTC FAN4855MTCX Package 8 Pin TSSOP 8 Pin TSSOP Packing Rails Tape and Reel Typical Application Input 1.6V to 4.5V FAN4855 On Off Low Battery Detect In Low Battery Detect Out 1 VIN 2 SHDN 3 LBI 4 LB0 GND 8 VL 7 VOUT 6 FB 5 Output 3.3V to 5V up to 0.5A ©2005 Fairchild Semiconductor Corporation .fairchildsemi. FAN4855 Rev. 1.0.1 FAN4855 500m A High Efficiency Boost Regulator with Adjustable Output, Shutdown...