ver.2010/09/03 1 white led driver for backlight njw4603 u . d . general description the njw4603 is a high effici ency multiple strings white led driver for back light. this device is composed with 3 channel consta nt current drivers an d step up switching regulator, and can dr ive up to 24pcs. led. each constant current driver is able to supply maximum of 80ma per channel, and the driver interval is performed by high precision current control of 2% typ. the njw4603 can control lu minance up to 100 : 4 by pwm signal input, and also features adjustable switching frequency of 10 0khz to 1mhz. when abnormal led lighting occurs, the fault terminal sends out signals no tifying the abnormality to the control de partments, such as cpu. the njw4603 operates over a wide supply voltage range from 6v to 35v makes the ic ideal for medium sized lcd backlights, such as car navigations, note pc, and applications for amusement device. package outline NJW4603V njw4603kt1 features ? constant current driver : 10ma ~ 80ma ? led current control : 2% ( typ. ) ? operating voltage : 6v ~ 35v ? switching frequency : 100khz to 1mhz ? led open / short protection ? fault signal output ? luminance control with pwm ? internal soft start ? under voltage lock out circuit ( uvlo ) ? built in over voltage / over current protection ? built in thermal shutdown protection ? package : NJW4603V ssop-32 njw4603kt1 qfn-24
ver.2010/09/03 2 application njw4603 ovp ocp current sink current setting feedback control ignd iset fbi fbo led open/short protection logic osc a gnd tsd uvlo regulator vdd ei flt eo ss pwm fsel reg en r fbi r iset r nf2 r nf1 c nf1 c ss c reg c in led3 led2 led1 ovp out q1 c out d1 l1 pgnd pgnd r t built in 40v mos fet constant current with open/short protection set up for led current 10ma to 80ma fault (error flag) pwm input luminance control adjustable oscillation frequency 100khz to 1mhz power supply 6v 35v
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