ec421 5 constant curre nt led driver with pwm dimming e - cmos corp. (ww w .e c mo s . c om.tw) 3d08n rev. f001 1 / 6 fe a tures ? universal input voltage range of 120va c 16% or 230vac 16% ? adjusted constant current operation ? low quiescent current ? simplifies circuit and system designs ? compact component count ? temperature compensated constant current ? over current protection ? over temperature protection ? led current thermal foldback for t hermal protection ? pwm dimming control ? dfn - 8l exposed pad package appl i c a tions ? led driver ? lighting applications ? lamp indicators ? candle light ? low cost solution ? co nstant current s ink general description the ec421 5 is a constant current linear high voltage led driver for replace discrete solutions in ac/dc power application (up to 2 70 v ac ). t he device can drive a n output power of 10 % variation from a universal input voltage range of 120va c 16%, or 230vac 16% for different led strings. the solution eliminates the need of individual components by combining them into a single package, which results in a significant reduction of both system cost and board space. the ec421 5 can as a constant current sink for high voltage led or low voltage led strings in series. for higher current application, multiple ec421 5 s can al so be used in parallel such as 6 0ma, 80ma or 160ma. the EC4215 is capable of a dimming input for adjustable l ed brightness control by pulse width modulation (pwm) . the ec421 5 is self - protected against over temperature and over current . internal thermal foldba ck function regulates led driv ing current automatically to limit die temperature during high power operati on or high ambient temperature conditions. these features provide maximum system protection for the demanding lighting applications. the ec421 5 is available in a s pace saving dfn - 8l exposed p ad package , an d th e operating temperature is from C 4 0 c to + 12 5c . typical application circuit fig. 1 simplified application circuit v led i led 1 2 3 4 8 7 6 5 v in r ext d im v ff gnd br 1 ac r e xt r 1 r 2 gnd gnd led
ec421 5 constant curre nt led driver with pwm dimming e - cmos corp. (ww w .e c mo s . c om.tw) 3d08n rev. f001 2 / 6 absolute m ax i mum r a tings v in , led supply voltage ................... ......... ........ . . . . . 5 5 0 v v ff , r ext , d im operation voltage . .. . .................. ..... . . ... 6 v operati n g t e mpera ture - 4 0 c to +12 5 c storage t e mperature - 5 5c to +150 c maximum d i e t e mperature . +150c le a d t e mperature. + 260 c esd hbm voltage hv pin .... . 1.2 kv esd hbm voltage lv pin .... .. 3 .5 kv esd m m voltage . .. 2 5 0 v pin configuration note: absolute maximum ratings are those values beyond which damage to the device may occur. functional operation under these conditions is not implied. continuous operation of the de vice at the absolute rating level may affect device reliability. ordering inf o r mation part no. package type marking information remark ec421 5 1nnf2r dfn - 8l EC4215 lllll yywwt yyww date code lllll lot no t internal t racking code electr i cal characterist i cs t a = 25 c u nless o the r w ise specif i ed parameter conditions min typ max unit electrical characteristic v in operation voltage 25 500 v i led current regulation (note 1) v in = 25 vdc, r ext =15 38 40 42 ma v in = 2 5 vd c, r ext = 30 19 20 21 ma i led(max) maximum current regulation v drop R 16v (note 2 ) 1 2 0 ma i q quiescent c urrent v in =2 5 vdc, r ext = open 1 5 0 a v ref reference voltage (note 3) 0.6 v v drop(max) maximum dropout voltage (note 4 ) v in = 2 65 v a c, r ext = 30 , v led = 220 v 17 0 v v dim - h d im pin high threshold v dim rising 1.4 v v dim - l d im pin low threshold v dim falling 0.4 v thermal characteristic v ref (t) v ref temperature coefficient t a = - 40 c ~1 25 c 0.01 / t a operating temperature - 40 125 p d tot al power dissipation (operation) 1 w r ja thermal resistance dfn - 8l package 33.2 /w protection ocp over current protection 180 ma otp over temperature protection 150 tfp thermal foldback protection 100 note: 1. i led =0.6/r ext , v ff =0 v, d im =0v, led=25v 2. v drop =v in v led , p d 1w (no heat sink) 3 . v r ef =v (r ext ) , v ff =0v, d im =0v 4. the current regulation is for an instantaneous ac line input current only, not to exceed thermal characteristics of packag e. top view fig. 2 detailed bloam dfn - 8 l r ext v in thermal pad 1 2 3 4 5 6 7 8 led v ff d im gnd gnd gnd
e - cmos corp. (ww w .e c mo s . c om.tw) ec 421 5 3d08n rev. f001 constant current led driver with pwm dimming 3 / 6 function diagram pin descriptions pin symbol description 1 v ff input voltage sensing through a voltage divider for constant output power regulation . 2 v in i nput supply voltage . 3 d im connect a logic level pwm signal for adjustable brightness of led strings. 4 r ext an external resistor sets different current regulation for led strings between r ext and gnd pin . 5 gnd ground. 6 gnd ground. 7 gnd ground. 8 led the led strings are connected from input supply voltage to th is pin . fig. 2 detailed bloam control circuits led gnd v ff r ext protection circuits d im v in
e - cmos corp. (ww w .e c mo s . c om.tw) ec 421 5 3d08n rev. f001 constant current led driver with pwm dimming 4 / 6 ec421 5 led lighting application circuit schematic 110 vac 4 w led lighting demo board part list component value package u1 ec 421 5 dfn - 8 l br1 b 10 s smd f1 1a dip rv1 221kd14 (140vac) dip r 1 1.2m eg 0603 r 2 6.19k 0603 r ext 10 0603 v led 1 1 0 v na 220 vac 4 w led lighting demo board part list component value package u1 ec 421 5 dfn - 8l br1 b 10 s smd f1 1a dip rv1 431kd14 (275vac) dip r 1 2.49 meg 0603 r 2 7.32 k 0603 r ext 19.1 0603 v led 2 2 0v na fig. 3 typical application circuit ac f 1 rv 1 v led i led 1 2 3 4 8 7 6 5 v in r ext d im v ff gnd br 1 r e xt r 1 r 2 gnd gnd led
e - cmos corp. (ww w .e c mo s . c om.tw) ec 421 5 3d08n rev. f001 constant current led driver with pwm dimming 5 / 6 ec421 5 led lighting with pwm dimming application circuit schematic fig. 4 typical application circuit with pwm dimming ac f 1 rv 1 v led i led 1 2 3 4 8 7 6 5 v in r ext d im v ff gnd br 1 r e xt r 1 r 2 gnd gnd led
e - cmos corp. (ww w .e c mo s . c om.tw) ec 421 5 3d08n rev. f001 constant current led driver with pwm dimming 6 / 6 dfn - 8 l package
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