? 2012 semtech corporation power management 1 SC5012 high efciency 4-ch, 150ma/ch led driver with i 2 c interface and phase-shifte d pwm dim ming revision 2.2 features input voltage 4.75v to 45v output voltage up to 65v step-up (boost) controller ultra-fast transient response programmable switching frequency external sync frequency for boost controller linear current sinks 4 strings, up to 150ma/string current matching 1% current accuracy 2% pwm dimming string-by-string phase shifting dimming frequency 100hz-30khz user selectable 9 or 10 bits dimming resolution optional synchronization to vsync/hsync signal external frequency synchronization, fsync 8-bit analog dimming i 2 c interface fault status open/short led, otp device control: sync freq, pll setting protection features open/shorted led(s) and adjustable ovp over-temperature 4mm x 4mm 24 ld qfn package applications medium-sized lcd panel automotive car navigation/information display lcd monitors ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? description the SC5012 is a 4-channel high-precision, high-efciency step-up (boost) hb led driver designed for backlight applications. it features wide input voltage range (4.75v to 45v) , fexible output confguration, wide analog and pwm dimming range, phase shifting, optional fading, external boost controller frequency synchronization (fsync), i 2 c interface, and numerous protection features. the boost controller, with programmable switching fre - quency from 200khz to 2.2mhz, can maximize efciency by dynamically minimizing the output voltage while maintaining led string current accuracy. it provides excel - lent line and load response with no external compensa - tion components. each linear current sink is matched within 1% for superb lighting uniformity, and the accu - racy of each string current is 2%. an external resistor adjusts the current from 40-150ma per string. it also fea - tures pwm dimming resolution of 9 or 10 bits (user select - able) over a 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. SC5012 is available in 4mm x 4mm 24 ld qfn package. typical application circuit d r v n c s a g n d is e t f s e t c p l l s c p v in s c 5 0 1 2 p w m i p w m i r 1 5 r 4 r 5 f l t c 2 1 v l d o f l t v c c s s s d a p g n d r 8 r 7 c 4 r 6 r 9 q 1 c 1 l 1 s y n c s y n c o v p r 1 0 r 1 1 v o u t u p to 6 5 v v in 4 . 7 5 to 4 5 v u p to 1 5 0 m a / c h i 2 c s c l i 2 c io 1 io 2 io 3 c 6 io 4 f s y n c f s y n c e n c 2 2 r 2 4 c 2 0 v l d o
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