RT8055GQW Richtek

RT8055 3A, 2MHz, Synchronous Step-Down Converter General Description Features zz z zz High Efficiency : Up to 95% The RT8055 is a high efficiency synchronous, step-down zz z zz Low R Internal Switches : 100m DS(ON) DC/DC converter. Its input voltage range is from 2.6V to zz z zz Programmable Frequency : 300kHz to 2MHz 5.5V and provides an adjustable regulated output voltage zz z zz No Schottky Diode Required from 0.8V to 5V while delivering up to 3A of output current. zz z zz 0.8V Reference Voltage Allows for Low Output The internal synchronous low on-resistance power Voltage switches increase efficiency and eliminate the need for zz z zz Forced Continuous Mode Operation an external Schottky diode. The switching frequency is zz z zz 100% Duty Cycle Operation set by an external resistor. The 100% duty cycle provides zz z zz Input Over Voltage Protection low dropout operation extending battery life in portable zz z zz RoHS Compliant and Halogen Free systems. Current mode operation with external compensation allows the transient response to be Applications optimized over a wide range of loads and output capacitors. z Portable Instruments The RT8055 is operated in forced continuous PWM Mode z Battery-Powered Equipment which minimizes ripple voltage and reduces the noise and z Notebook Computers RF interference. z Distributed Power Systems The RT8055 is available in the WDFN-10L 3x3 and z IP Phones SOP-8 (Exposed Pad) packages. z Digital Cameras z 3G/3.5G Data Card Ordering Information Pin Configurations RT8055 (TOP VIEW) Package Type QW : WDFN-10L 3x3 (W-Type) 1 10 SHDN/RT COMP SP : SOP-8 (Exposed Pad-Option 2) 2 9 GND FB 3 LX 8 VDD Lead Plating System 4 7 PVDD LX 5 11 6 PGND PVDD G : Green (Halogen Free and Pb Free) Z : ECO (Ecological Element with Halogen Free and Pb free) WDFN-10L 3x3 Note : Richtek products are : 8 SHDN/RT COMP RoHS compliant and compatible with the current require- 2 7 GND FB GND ments of IPC/JEDEC J-STD-020. 3 6 LX VDD 9 4 5 PGND PVDD Suitable for use in SnPb or Pb-free soldering processes. SOP-8 (Exposed Pad) Copyright 2012 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. DS8055-05 November 2012 www.richtek.com 1 GNDRT8055 Marking Information RT8055GQW RT8055GSP JN= : Product Code RT8055GSP : Product Number RT8055 YMDNN : Date Code YMDNN : Date Code JN=YM GSPYMDNN DNN RT8055ZQW JN : Product Code YMDNN : Date Code JN YM DNN Typical Application Circuit L1 2H V IN V OUT PVDD LX 5V 3.3V/3A C C1 IN RT8055 C OUT 22F 0.1F R1 VDD 22F x 2 75k FB R OSC R2 180k 24k SHDN/RT COMP R COMP GND 30k PGND C COMP 470pF Table 1. Recommended Component Selection V R1 (k ) R2 (k ) R (k ) C (nF) L1 (H) C (F) OUT COMP COMP OUT 3.3 75 24 30 0.47 2.2 22 x 2 2.5 51 24 27 0.47 2.2 22 x 2 1.8 30 24 22 0.47 2.2 22 x 2 1.5 21 24 18 0.47 2.2 22 x 2 1.2 12 24 15 0.47 1.0 22 x 2 1.0 6 24 13 0.47 1.0 22 x 2 Copyright 2012 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. www.richtek.com DS8055-05 November 2012 2