Semtech(升特)公司的 SC5010是超薄筆記本面板用的相移式8通道白光LED背光驅(qū)動器,采用創(chuàng)新的PWM相移調(diào)光控制法,可使用1mm高的2.2μH微型電感，用于高效超薄的4mm厚度顯示器.SC5010提供精確的背光色溫以及全屏一致的亮度，通道間的電流匹配度為+/-1%，精度為+/-1.5%。它有完備的保護功能，包括LED開路保護和可編程的LED短路保護、可調(diào)過壓保護（OVP），以及過熱保護；另外還有欠壓鎖定（UVLO）關斷功能。器件輸入電4.5V至27V；輸出電壓最高達50V, 最高效率達92%,最多可驅(qū)動112只白光LED,主要用在超薄筆記本電腦,UMPC,LCD監(jiān)視器和平板電腦.本文介紹了SC5010主要特性,方框圖,LED PWM調(diào)光控制框圖,詳細應用電路以及SEPIC配置圖,高輸出電壓應用電路圖.
The SC5010 is an 8-channel high-precision, high-effi ciency step-up (Boost) LED driver for backlight applications. It features wide input voltage range (4.5V to 27V) , fl exible output configuration, wide analog and PWM dimming range, phase shifting and fading. It also features video signal synchronization (VSYNC), I2C interface, and numerous protection features. An optional disconnect p-MOSFET provides true load disconnection and inrush current limiting.
The boost controller, with programmable switching frequency from 200kHz to 2.2MHz, maximizes effi ciency by dynamically minimizing the output voltage while maintaining LED string current accuracy. It provides excellent line and load response with no external compensation components.
Each linear current sink is matched within ±1% for superb lighting uniformity, and the accuracy of each string current is ±1.5%. An external resistor adjusts the current from 10-30mA per string. It also features PWM dimming resolution of 9 or 10 bits (user selectable) over dimming frequency from 100Hz to 20kHz, synchronized to the SYNC signal or the boost oscillator. String-by-string phase shifting reduces the demand on the input/output capacitance, decreases EMI, and improves dimming linearity.
SC5010 is available in a low-profi le, thermally enhanced, 4 X 4 X 0.6(mm) QFN 28-pin package.
SC5010主要特性:
VIN Range — 4.5V to 27V, VOUT Range — Up to 50V
Step-up (Boost) Controller
Excellent Transient Response
Programmable Switching Frequency
Linear Current Sinks
8 Strings, up to 30mA/String
Current Matching ±1%
Current Accuracy ±1.5%
PWM Dimming
String-by-String Phase Shifting
Input Dimming Frequency 100Hz-30kHz
User Selectable 9 or 10 Bits Dimming Resolution
Optional Synchronization to VSYNC/HSYNC Signal
5-bit Analog Dimming
Optional External p-MOSFET Disconnect Switch
True Load Disconnect and Inrush Current Limiting
I2C Interface
Fault Status — Open/Short LED, UVLO, OTP
Device Control — SYNC Freq, PLL Setting
Protection Features
Open/Shorted LED(s) and adjustable OVP
Over-Temperature and UVLO Shutdown Protection
4 X 4(mm) 28-pin QFN Package
SC5010應用:
Notebook PCs, UMPC, LCD Monitors, and Tablet PCs
圖1.SC5010方框圖
圖2.SC5010 LED PWM調(diào)光控制框圖
圖3.SC5010典型應用電路圖
圖4.SC5010詳細的應用電路圖
圖5.SC5010 SEPIC配置圖
圖6.SC5010高輸出電壓應用電路圖
詳情請見:
http://www.semtech.com/images/datasheet/sc5010.pdf
