e l ek tr on isch e b a u e lemen te s j1084 5a low dropout positive adjustable or fixed-mode regulator d e s c r i p t i o n the SJ1084 is a low dropout at positive adjustable or fixed-mode regulator with min. of 5a output current capability. the product is specifically designed to provide well-regulated supply for low voltage ic applications such as high-speed bus termination and low current 3.3v logic supply. SJ1084 is also well suited for other applications such as vga cards. SJ1084 is guaranteed to have lower than 1.5v dropout at full load current making it ideal to provide well regulated outputs of 1.25v to 3.3v with 4.7 to 12v input supply. * 3-terminal adjustable or f ixed 1.5v,1.8v,2.5v,3.3v,5.0v f e a t u r e s * 1.5 v max. dropout full load current * output current limiting * good noise rejection * fast transient response * built-in thermal shutdown 01 -jun-2002 rev. a page 1 of 4 http://www.secosgmbh.com/ any changing of specification will not be informed individual r o h s c o m p l i a n t p r o d u c t typical circuit block diagram to-252 r ef . m i n . m a x . r ef . m i n . m a x . a 6 . 4 0 6 . 8 0 g 0 . 5 0 0 . 7 0 b 5 . 2 0 5 . 5 0 h 2 . 2 0 2 . 4 0 c 6 . 8 0 7 . 2 0 j 0 . 4 5 0 . 5 5 d 2 . 2 0 2 . 8 0 k 0 0 . 1 5 e 2 . 3 0 r e f . l 0 . 9 0 1 . 5 0 f 0 . 7 0 0 . 9 0 m 5 . 4 0 5 . 8 0 s 0 . 6 0 0 . 9 0 r 0 . 8 0 1 . 2 0 millmeter millmeter
dc supply voltage power dissipation storage temperature range operating juction temperature range parameter symbo l ratings unit v v in -0.3 to 12 0~+150 -65~+150 a b s o l u t e m a x i m u m r a t i n g s p d t st t op c o c o internally limited e l e k t r o n i s c h e b a u e l e m e n t e h t t p : / / w w w . s e c o s g m b h . c o m / a n y c h a n g i n g o f s p e c i f i c a t i o n w i l l n o t b e i n f o r m e d i n d i v i d u a l 01-jun-2002 rev. a page 2 of 4 p i n d e s c r i p t i o n s n a m e i / o p i n # f u n c t i o n ad j (g n d ) 1 ad j u s t a b l e (g r o u n d o n l y f o r f i x e d m o d e ) v o u t o 2 t h e o u t p u t o f t h e r e g u l a t o r . a m i n i m u m o f 1 0 u f c a p a c i t o r m u s t b e c o n n e c t e d f r o m t h i s p i n t o g r o u n d t o i n s u r e s t a b i l i t y . v i n i 3 s n o t s a g b e l o w t h e m i n i m u m d r o p o u t v o l t a g e d u ri n g t h e l o a d v h i g h e r t h a n v o u t i n o r d e r f o r t h e d e v i c e t o e l e c t r i c a l c h a r a c t e r i s t i c s s y m b o l p a r a m e t e r c o n d i t i o n s ( n o t e s ) m i n t y p m a x u n i t v r e f s j 1 0 8 4 ad j i o = 1 0 m a , t j = 2 5 : , (vi n - v o u t ) = 1 . 5 v 1 . 2 2 5 1 . 2 5 0 1 . 2 7 5 v s j 1 0 8 4 -1 . 5 i o = 1 0 m a , t j = 2 5 , : 3 . 0 v v i n 1 2 v 1 . 4 7 0 1 . 5 0 0 1 . 5 3 0 v s j 1 0 8 4 -1 . 8 i o = 1 0 m a , t j = 2 5 , : 3 . 3 v v i n 1 2 v 1 . 7 6 4 1 . 8 0 0 1 . 8 3 6 v s j 1 0 8 4 -2 . 5 i o = 1 0 m a , t j = 2 5 , : 4 . 0 v v i n 1 2 v 2 . 4 5 0 2 . 5 0 0 2 . 5 5 0 v s j 1 0 8 4 -3 . 3 i o = 1 0 m a , t j = 2 5 , : 4 . 8 v v i n 1 2 v 3 . 2 3 5 3 . 3 0 0 3 . 3 6 5 v o u t p u t v o l t a g e s j 1 0 8 4 -5 . 0 i o = 1 0 m a , t j = 2 5 , : 6 . 5 v v i n 1 2 v 4 . 9 0 0 5 . 0 0 0 5 . 1 0 0 v l i n e r e g u l a t i o n s j 1 0 8 4 xxx i o = 1 0 m a , v o u t + 1 . 5 v< v i n < 1 2 v , t j = 2 5 : - - 0 . 2 % s j 1 0 8 4 ad j v i n = 3 . 3 v , 0 m a< i o < 5 a, t j = 2 5 (n o t e 1 , 2 ) : - - 1 % s j 1 0 8 4 -1 . 5 v i n = 3 . 0 v , 0 m a< i o < 5 a, t j = 2 5 (n o t e 1 , 2 ) : - 1 2 1 5 m v s j 1 0 8 4 -1 . 8 v i n = 3 . 3 v , 0 m a< i o < 5 a, t j = 2 5 (n o t e 1 , 2 ) : - 1 5 1 8 m v s j 1 0 8 4 -2 . 5 v i n = 4 . 0 v , 0 m a< i o < 5 a, t j = 2 5 (n o t e 1 , 2 ) : - 2 0 2 5 m v s j 1 0 8 4 -3 . 3 v i n = 5 . 0 v , 0 m a< i o < 5 a, t j = 2 5 (n o t e 1 , 2 ) : - 2 6 3 3 m v l o a d r e g u l a t i o n s j 1 0 8 4 -5 . 0 v i n = 8 . 0 v , 0 m a< i o < 5 a, t j = 2 5 (n o t e 1 , 2 ) : - 4 0 5 0 m v v o d r o p o u t v o l t a g e i o = 5 . 0 a( v o u t = 1 % v o u t ) - 1 . 4 1 . 5 v i l i m c u rr e n t l i m i t v i n -v o u t = 5 v 5 . 1 - - a i m i n m i n i m u m l o a d c u r r e n t v i n = 5 v ( a d j u s t a b l e m o d e l ) - 5 1 0 m a i a d j ad j u s t p i n c u rr e n t v i n = 1 2 v , i o = 1 0 m a - 5 5 1 0 0 u a i q q u i e s c e n t c u rr e n t v i n = 1 2 v , i o = 0 m a (f i x e d m o d e l ) - - 1 2 m a t e m p e r a t u r e s t a b i l i t y i o = 1 0 m a - 0 . 5 - % j a t h e rm a l r e s i s t a n c e j u n c t i o n -t o -a m b i e n t ( n o h e a t s i n k ; n o a i r f l o w ) - 9 8 - / : w j c t h e rm a l r e s i s t a n c e j u n c t i o n -t o -c a s e - 1 5 - / : w n o t e 1 : s e e t h e r m a l r e g u l a t i o n s p e c i f i c a t i o n s f o r c h a n g e s i n o u t p u t v o l t a g e d u e t o h e a t i n g e f f e c t s . l i n e a n d l o a d r e g u l a t i o n a r e m e a s u r e d a t a c o n s t a n t j u n c t i o n t e m p e r a t u r e b y l o w d u t y c y c l e p u l s e t e s t i n g . l o a d r e g u l a t i o n i s m e a s u r e d a t t h e o u t p u t l e a d = 1 / 1 8 f ro m t h e p a c k a g e . n o t e 2 : l i n e a n d l o a d r e g u l a t i o n a r e g u a r a n t e e d u p t o t h e m a x i m u m p o w e r d i s s i p a t i o n o f 1 5 w . po w e r d i s s i p a t i o n i s d e t e r m i n e d b y t h e d i f f e r e n c e b e t w e e n i n p u t a n d o u t p u t a n d t h e o u t p u t c u rr e n t . g u a r a n t e e d m a x i m u m p o w e r d i s s i p a t i o n w i l l n o t b e a v a i l a b l e o v e r t h e f u l l i n p u t / o u t p u t r a n g e . s j1084 5 a low dropout positive adjustable or f i xed-mode regulator t h e i n p u t p i n o f r e g u l a t o r . t y p i c a l l y a l a rg e s t o r a g e c a p a c i t o r i s c o n n e c t e d f r o m t h i s p i n t o g r o u n d t o i n s u r e t h a t t h e i n p u t v o l t a g e d o es not sag below the minimum dropout voltage during the load t r a n s i e n t r e s p o n s e . t h i s p i n m u s t a l w a y s b e 1 .5v higher than vout in order for the device to r e g u l a t e p r o p e rl y .
01-jun-2002 rev. a page 3 of 4 h t p : / / w w w . s e c o s g m b h . c o m / a n y c h a n g i n g o f s p e c i f i c a t i o n w i l l n o t b e i n f o r m e d i n d i v i d u a l e l e k t r o n i s c h e b a u e l e m e n t e f u n c t i o n a l d e s c r i p t i o n i n t r o d u c t i o n t h e s j1 0 8 4 a d j u st a b l e l o w d r o p o u t ( l d o ) r e g u l a t o r i s a 3 t e r m i n a l d e vi ce t h a t ca n e a si l y b e p r o g r a m m e d w i t h t h e a d d i t i o n o f t w o e x t e r n a l r e si s t o r s t o a n y vo l t a g e s w i t h i n t h e r a n g e o f 1 . 2 5 v t o 2 . 5 v . t h e s j1 0 8 4 o n l y n e e d s 1 . 5 v d i f f e r e n t i a l b e t w e e n v i n a n d v o u t t o m a i n t a i n o u t p u t r e g u l a t i o n , t h e o u t p u t vo l t a g e t o l e r a n ce s a r e a l so e x t r e m e l y t i g h t a n d t h e y i n cl u d e t h e t r a n si e n t r e sp o n se a s p o r t o f t h e sp e ci f i c a t i o n . f o r e xa m p l e , i n t e l v r e sp e ci f i ca t i o n ca l l s f o r a t o t a l o f + / - 1 0 0 m v i n c l u d i n g i n i t i a l t o l e r a n ce , l o a d r e g u l a t i o n a n d 0 t o 5 . 0 a l o a d s t e p . t h e s j 1 0 8 4 i s s p e ci f i ca l l y d e si g n e d t o m e e t t h e f a st cu r r e n t t r a n s i e n t n e e d s a s w e l l a s p r o v i d i n g a n a ccu r a t e i n i t i a l vo l t a g e , r e d u ci n g t h e o ve r a l l sy st e m c o st w i t h t h e n e e d f o r f e w e r o u t p u t ca p a ci t o r s. o u t p u t v o l t a g e s e t t i n g t h e s j1 0 8 4 ca n b e p r o g r a m m e d t o a n y vo l t a g e s i n t h e r a n g e o f 1 . 2 5 v t o 5 v w i t h t h e a d d i t i o n o f r 1 a n d r 2 e x t e r n a l r e si st o r s a cc o r d i n g t o t h e f o l l o w i n g f o r m u l a : t h e s j1 0 8 4 ke e p s a co n st a n t 1 . 2 5 v b e t w e e n t h e o u t p u t p i n a n d t h e a d j u s t p i n . b y p l a c i n g a r e si s t o r r 1 a c r o ss t h e se t w o p i n s a co n st a n t cu r r e n t f l o w s t h r o u g h r 1 , a d d i n g t o t h e i a d j cu r r e n t r e q u i r e m e n t o f t h e g j1 0 8 4 i s 1 0 m a , r 1 i s t yp i ca l l y se l e ct e d t o b e 1 2 1 r e si st o r so t h a t i t a u t o m a t i ca l l y sa t i sf i e s t h e m i n i m u m cu r r e n t r e q u i r e m e n t . n o t i ce t h a t si n ce i a d j i s t yp i ca l l y i n t h e r a n g e o f 5 5 u a i t o n l y a d d s a s m a l l e r r o r t o t h e o u t p u t vo l t a g e a n d sh o u l d o n l y b e co n si d e r e d w h e n a ve r y p r e ci se o u t p u t vo l t a g e se t t i n g i s r e q u i r e d . f o r e x a m p l e , i n a t yp i ca l 3 . 3 v a p p l i ca t i o n w h e r e r 1 = 1 2 1 a n d r 2 = 2 0 0 t h e e r r o r d u e t o i a d j i s o n l y 0 . 3 % o f t h e n o m i n a l se t p o i n t . l o a d r e g u l a t i o n s i n ce t h e s j 1 0 8 4 i s o n l y a 3 t e r m i n a l d e vi ce , i t i s n o t p o s si b l e t o p r o v i d e t r u e r e m o t e se n si n g o f t h e o u t p u t v o l t a g e a t t h e l o a d . t h e b e st l o a d r e g u l a t i o n i s a ch i e ve d w h e n t h e b o t t o m si d e o f r 2 i s co n n e ct e d t o t h e l o a d a n d t h e t o p - si d e o f r 1 r e si s t o r i s co n n e ct e d d i r e ct l y t o t h e ca se o r t h e v o u t p i n o f t h e r e g u l a t o r a n d n o t t o t h e l o a d . i t i s i m p o r t a n t t o n o t e t h a t f o r h i g h cu r r e n t a p p l i ca t i o n s , t h i s ca n r e - p r e se n t a s i g n i f i c a n t p e r ce n t a g e o f t h e o ve r a l l l o a d r e g u l a t i o n a n d o n e m u st ke e p t h e p a t h f r o m t h e r e g u l a t o r t o t h e l o a d a s s h o r t a s p o ss i b l e t o m i n i m i z e t h i s e f f e ct . s t a b i l i t y t h e s j1 0 8 4 r e q u i r e s t h e u se o f a n o u t p u t ca p a c i t o r a s p a r t o f t h e f r e q u e n cy c o m p e n sa t i o n i n o r d e r t o m a ke t h e r e g u l a t o r st a b l e . f o r m o st a p p l i c a t i o n s a m i n i m u m o f 1 0 u f a l u m i n u m e l e ct r o l y t i c ca p a c i t o r i n su r e s b o t h st a b i l i t y a n d g o o d t r a n s i e n t r e sp o n se . t h e r m a l d e s i g n t h e s j1 0 8 4 i n co r p o r a t e s a n i n t e r n a l sh u t d o w n t h a t p r o t e ct s t h e d e vi ce w h e n t h e j u n c t i o n t e m p e r a t u r e e x c e e d s t h e m a x i m u m a l l o w a b l e j u n c t i o n t e m p e r a t u r e s. a l t h o u g h t h i s d e vi ce ca n o p e r a t e w i t h j u n c t i o n t e m p e r a t u r e s i n t h e r a n g e o f 1 5 0 , : : : : i t i s r e co m m e n d e d t h a t t h e se l e ct e d h e a t si n k b e ch o se n su ch t h a t d u r i n g m a x i m u m co n t i n u o u s l o a d o p e r a t i o n t h e j u n c t i o n t e m p e r a t u r e i s ke p t b e l o w t h e t e m p e r a t u r e . l a y o u t c o n s i d e r a t i o n t h e o u t p u t ca p a c i t o r s m u s t b e l o c a t e d a s c l o se t o t h e v o u t t e r m i n a l o f t h e d e vi ce a s p o ss i b l e . i t i s r e co m m e n d e d t o u se a se ct i o n o f a l a ye r o f t h e p c b o a r d a s a p l a n e t o co n n e ct t h e v o u t p i n t o t h e o u t p u t ca p a c i t o r s t o p r e ve n t a n y h i g h f r e q u e n cy o sci l l a t i o n t h a t m a y r e su l t d u e t o e x ce ssi ve t r a ce i n d u ct a n ce . s j 1 0 8 4 a d j s j1084 5 a low dropout positive adjustable or f i xed-mode regulator
01-jun-2002 rev. a page 4 of 4 h t p : / / w w w . s e c o s g m b h . c o m / a n y c h a n g i n g o f s p e c i f i c a t i o n w i l l n o t b e i n f o r m e d i n d i v i d u a l e l e k t r o n i s c h e b a u e l e m e n t e p e r f o r m a n c e c h a r a c t e r i s t i c s s j1084 5 a low dropout positive adjustable or f i xed-mode regulator
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