www. belling .com.cn 1 wide range, linear led driver BL8585 description the BL8585 is a high - voltage adjustable current source with accurate temperature compensation . the device is designed to provide a constant current source determined by an external sense resistor r sense . t he current is adjustable from 10ma to 20ma with less than 10% error while input changes from 5v to 90v. with an external resistor (r1 in figure 1) between va and is pin, the heat in the ic can be significantly reduced while keeping the summation of ic and r1 current to be constant. this is ex tremely useful in the area that power lines are not very stable. a typical application for the BL8585 is to drive leds with a constant current varies from 10 - 20ma. they can also be used in parallel to provide higher current according to the bias. this devi ce is available in to - 92 package. typical application circuit features ? wide operation range: from 5v to 90v(v a - b ) ? to - 92 packages available ? i led can be programmed from 10ma to 20ma via changing r sense ? power dissipation can be adjusted ? easy to use, only 3 pins and very little ext ernal components are needed ? can be paralleled for higher current ? temperature compensated applications ? industrial lamp indicators ? led driver ? accent lighting ? automotive ? constant current source ? constant current sink pin configurations { r sense r1 v led BL8585
www. belling .com.cn 2 BL8585 marking information marking information marking description 8585 yybzz 8585 product code yy lot no. b fab code zz date code ordering information BL8585 1 2 3 code description 1 temperature & rohs: c: - 40~85 ? c,pb free rohs std. 2 package type: h : to - 92 3 packing type: pt: paper type bg: bag ( to - 92) absolute maximum rating na me symbol value unit max supply voltage v a - b 90 v thermal resistance ja 170 /w maximum junction temperature t j 150 storage temperature tst - 55 to150 electrical characteristics block diogram symbol item conditions min typ max unit v a - b operating input volt age n/a 5 90 v i a - b current regulation v a - b =5 - 90v, i set =20ma - 10 +10 % v is current sense voltage 0.6 v t j operating junction temperature - 45 125
www. belling .com.cn 3 BL8585 operation the BL8585 is a high voltage integrated constant cu rrent driver. it can operate in a wide range from 5v to 90v, and the output current can be programmed just by change the sense resistor . this module provides a precise regulated output current, the typical application is showed in figure 1. as the BL8585 is a linear power supply, with high input voltage, the power dissipation should be considered. for example, if the set current is 20ma, when the v a - b is 5v, the module dissipation if the v a - b is 90v, the power dissipation is as hi gh as 1.8w. an external resistor r1 can be added to reduce the power dissipation of the BL8585 . then the power dissipation on the ic becomes when the ambient temperature is fixed, from thermal resistance value, the maximum power d issipation of the ic can be calculated. say the maximum allowed temperature increase is 50 ? c, with to - 92 package (170 ? c/w thermal resistance), the maximum allowed power dissipation is 0.29w. assume the maximum v a - b is 50v, i set = 20ma, and v sense = 0.6v. t hen r1 s power requirement can be calculated by rsense can be calculated from sense voltage and current set: figure1: typical application circuit r1 rsense i set BL8585 w p i v p d set b a d 1 . 0 ? ? ? ? ? ) ( 1 r v v i v p sense b a set b a d ? ? ? ? ? ? ? ? ? ? ? ? ? k v p i v v r b a d set sense b a 5 . 3 ) /( ) ( 1 w r v p b a r 71 . 0 1 2 1 ? ? ? ? ? ? 30 set is sense i v r l c 1 9 2 0 i s v a v b u p t o 9 0 v + v l e d
www. belling .com.cn 4 BL8585 performance characteristics (all the test done at i set =20ma) output current vs v a - b temperature characteristics v a-b vs output current 0 5 10 15 20 25 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 v a-b (v) i a-b (ma) i a-b vs temperature 19.0 19.5 20.0 20.5 21.0 21.5 -50 -25 0 25 50 75 100 125 temp() i a-b (ma) va-b=6v va-b=45v
www. belling .com.cn 5 BL8585 application circuits figure2: for large current use figure3: for high input voltage use figure4: for multiple led strings use BL8585 BL8585 BL8585 BL8585 BL8585 BL8585 BL8585 BL8585 l c 1 9 2 0 i s v a v b u p t o 9 0 v + v l e d l c 1 9 2 0 i s v a v b l c 1 9 2 0 i s v a v b l c 1 9 2 0 i s l c 1 9 2 0 i s v a v a v b v b u p t o 1 8 0 v + v l e d l c 1 9 2 0 i s v a v b u p t o 9 0 v + v l e d l c 1 9 2 0 i s v a v b l c 1 9 2 0 i s v a v b
www. belling .com.cn 6 BL8585 package information package to - 92 devices per reel 3 000 pcs unit mm package dimension
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