UC3550

UNISONIC TECHNOLOGIES CO., LTD UC3550 PWM CONTROLLED, PWM/PFM SWITCHABLE STEP-UP DC-DC CONTROLLER „ DESCRIPTION The UTC UC3550 series is a compact, high efficiency, step-up DC/DC controllers includes an error amplifier, oscillator, PWM comparator, skip cycle comparator, voltage reference, soft-start, and high speed lower ON-resistance driver for driving external power devices (NMOS or NPN) ,Additionally, a CE (chip enable) function that reduces power consumption during shut-down mode. That typically operated from a single-or dual-cell battery packs. It have a driver pin ,ext pin, for connecting to an external transistor(NMOS or NPN). a lower ON-resistance external transistor can obtain larger output current. With only external components, this series allow a simple means to accommodate high output current applications. The UTC UC3550 series goes automatically into skip switching cycles under light load condition to maintain high efficiency. 5 „ FEATURES * Input Voltage Range：0.9~8V * Output Voltage Range：1.8~6V Programmable in 0.1V with High Accuracy ± 2.5% * High Efficiency 88% (Typ.) * Low Start-up Voltage of 0.9V Typical at IOUT = 1.0mA * Oscillator Frequency: 300kHz.(±20%) * Chip Enable Pin with Pull-up Current Source * High Output Current up to 1000mA (VIN = 2.0V, VOUT =3.3V) „ ORDERING INFORMATION Ordering Number Lead Free Halogen Free UC3550L-xx-AF5-R UC3550G-xx-AF5-R Package SOT-25 CMOS IC 4 3 12 SOT-25 Packing Tape Reel www.unisonic.com.tw Copyright © 201...