EMD2055

ESMT/EMP Preliminary EMD2055 PWM Step-Up DC/DC Converter for Panel Backlight (11 WLEDs Driver) General Description The EMD2055 is a highly efficient, step-up DC/DC converter for driving white LEDs. The device can drive up to 11 serially connected white LEDs from a single Li-Ion battery, or to drive multiple serial and parallel combinations with a DC power supply from 2.5V to 5.5V. The EMD2055 uses current mode and pulse-width modulated (PWM) operation. Its high switching operation frequency of 1.0MHz allows the system to use small inductor, input and output capacitors. An internal compensation circuit can reduce the external component count. Applications Mobile Phone Digital Still Cameras Portable applications MP3 Players GPS Receivers Features Up to 11 WLEDs supports Low Quiescent Current: 120 µA Over Voltage Protection: 36.5V Inherently Matched LED Current Shutdown Current < 1µA To safeguard the system, the EMD2055 includes various protection circuits such as under-voltage lockout, current limit, over voltage and thermal shutdown. EMD2055 are available in the tiny packages of SOT-23-6L and TDFN-8L (2x2mm). Reference Voltage 0.24V PWM Dimming Control (100Hz~100kHz) Internal Soft Start and Compensation 1.5A Internal power MOSFET Switch Low Profile SOT-23-6 and TDFN-8L Packages Typical Application (9S3P) Fig. 1 Elite Semiconductor Memory Technology Inc./Elite MicroPower Inc. Publication Date: Jan. 2013 Revision: 0.03 1/13 ESMT/EMP Connection Diagram Preliminary O...