基于SC442設(shè)計(jì)的高效120個(gè)白光LED驅(qū)動(dòng)技術(shù)
SC442是10路高效120個(gè)白光LED驅(qū)動(dòng)器,輸入電壓4.5V-21V,高效的升壓轉(zhuǎn)換器可使輸出電壓高達(dá)42V,非常適合中到大型LCD顯示屏。電流沉可編程,每路高達(dá)30mA,路間的電流匹配在+/-1%,集成了3A開(kāi)關(guān),效率高達(dá)91%,可靈活進(jìn)行LED配置,高達(dá)50kHz調(diào)光頻率,大于500:1調(diào)光范圍,開(kāi)關(guān)頻率500kHz - 1MHz,主要用在汽車LCD背光,臺(tái)式監(jiān)視器,筆記本電腦和手提TV。
SC442主要特性:
Wide input voltage range from 4.5V to 21V
42V maximum operating output voltage
Programmable LED current up to 30mA per string
+/- 1% current matching
Integrated 3A switch
Low current sink voltage
Up to 91% efficiency
Flexible LED configurations
Mismatched LED channels
Disable individual channel(s)
Parallel channels for high LED current
PWM dimming capability
Up to 50kHz dimming frequency
>500:1 dimming range
Switching frequency: 500kHz - 1MHz
Parallel device operation with Sync Pin
Protection features:
Adjustable OVP
Cycle-by-cycle current limit
LED short channel with disable /Open channnel
Over-Temperature protection
MLPQ-28 lead-free package (WEEE and RoHS compliant), 4×4mm × 0.6mm
SC442應(yīng)用:
Automotive LCD Backlighting
Desktop monitors
Notebook PCs
Portable TVs
圖1。SC442典型應(yīng)用電路
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