ver.2010/09/03 1 white led driver for backlight njw4600 u . d . general description the njw4600 is a high effici ency multiple strings white led driver for back light.this device is composed with 4channel constant current drivers and step up switching regulator, and can dr ive up to 32pcs. led. each constant current driver is able to supply maximum of 120ma per channel, and the driver interval is performed by highly precise current control of 2% typ. the njw4600 can control lu minance up to 100 : 4 by pwm signal input, and also features selectable switching frequency of 80 0khz or 1mhz. when abnormal led lighting occurs, the fault terminal sends out signals noti fying the abnormality to the control departments, such as cpu. the njw4600 operates over a wide supply voltage range from 6v to 35v, and operating temperature is up to 105oc. this very wide operating temperature range makes the ic ideal for medium sized lcd backlights, such as car navigations, no te pc, and appl ications for amusement device. package outline NJW4600V njw4600kt1 feature ? constant current dr iver : 10ma ~ 120ma ? led current control : 2% ( typ. ) ? operating voltage : 6v ~ 35v ? switching frequency : 800khz / 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 protection ? built in over current protection ? built in thermal shutdown protection ? package : NJW4600V ssop-32 njw4600kt1 qfn-24
ver.2010/09/03 2 led4 ovp cs led3 led2 led1 ocp current sink ovp ext 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 nf3 r cs q1 c out d1 l1 r nf1 c nf1 c ss c reg c in application power supply 6v 35v select oscillation frequency low: 800khz high:1mhz pwm input luminance control fault (error flag) set up for led current 10ma to120ma thermal shut down over current protection over voltage protection constant current with open/short protection njw4600
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