e l ek tr on isch e b a u e lemen te s q21 23 cmos positive voltage regulator * factory pre-set output voltage f e a t u r e s * high accurate * over-temperature shutdown 1.5% * very low dropout voltage * noise reduction bypass capacitor * short circuit current fold-back * guaranteed 300ma output * current limiting * portable electronics applications * pc peripherals * wireless devices * battery powered widgets * electronic scales * instrumentation * cordless phones and current fold-back to prevent device failure under the "worst" of operating conditions. in applications requiring a low noise, regulated supply, place a 1000pf capacitor between bypass and ground. the SQ2123 is stable with an output capacitance of 2.2mf or greater. 01 -jun-2002 rev. a page 1 of 7 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 application circuit functional block diagram r e f . m i n . m a x . r e f . m i l l i m e t e r a 2 . 7 0 3 . 1 0 g 1 . 9 0 r e f . b 2 . 6 0 3 . 0 0 h 1 . 2 0 r e f . c 1 . 4 0 1 . 8 0 i 0 . 1 2 r e f . d 0 . 3 0 0 . 5 5 j 0 . 3 7 r e f . e 0 0 . 1 0 k 0 . 6 0 r e f . f 0 1 0 l 0 . 9 5 r e f . dimensions m i l l i m e t e r * power-saving shutdown mode s q 2 1 2 3 i n o u t b y p g n d e n o u t i n + c 1 c 3 1 u f 2 . 2 u f c 2 1 0 0 0 p f description the sq21 23 series of positive,linear regulators feature low quiescent current (30ma typ.) with low dropout voltage, making them ideal for battery applications. these rugged devices have both thermal shutdown,
t c i s c p s r r e n 1 5 0 3 0 0 4 n o t e v _ _ _ _ _ _ _ _ _ _ _ i n p u t v o l t a g e o v e r t e m p e r a t u r e s h u t d o w n o v e r t e m p e r a t u r e h y s t e r s i s o u t p u t v o l t a g e t e m p e r a t u r e c o e f f i c i e n t s h o r t c i r c u i t c u r r e n t o u t p u t v o l t a g e n o i s e v i n o t s o t h 3 7 3 0 3 0 1 5 0 6 0 5 0 2 0 3 0 _ _ _ _ _ c o c o p p m / m a d b u v r m s c o v i n = v o u t ( t ) + 1 v , v o u t < 0 . 8 v f = 1 0 0 h z f = 1 k h z f = 1 0 k h z c o = 2 . 2 u f i o = 1 0 0 m a c o = 2 . 2 u f f = 1 0 h z ~ 1 0 0 k h z i o = 1 0 m a - 0 . 4 0 . 2 0 . 4 4 . 0 v < v ( t ) o u t r e g l i n e l i n e r e g u l a t i o n i 3 0 0 . 0 2 - 0 . 2 0 . 1 a % v = v ( t ) + 1 v , i o = 0 m a _ _ 5 0 - 0 . 1 5 - 0 . 1 0 . 2 0 . 1 5 i o = 1 m a v i n = v o u t ( t ) + 1 t o v o u t ( t ) + 2 1 . 2 v v o u t ( t ) 1 . 4 v 1 . 4 v < v o u t ( t ) 2 . 0 v 2 . 0 v < v o u t ( t ) < 4 . 0 v p o w e r s u p p l y r e j e c t i o n v e h i e h i s d 0 . 1 _ _ _ _ _ _ g r o u n d p i n c u r r e n t e n i n p u t t h r e s h o l d i g n d 3 5 2 0 0 . 5 0 . 5 0 1 0 . 4 _ _ u a u a v v v e n = v i n , v i n = 2 . 7 v v i n = 5 v , v o = 0 v , v e n < v e l i o = 0 . 4 m a , v e n < v e l s h u t d o w n s u p p l y c u r r e n t v i n = v o u t ( t ) + 2 v , i o = 1 m a ~ 3 0 0 m a v e l _ v i n 0 . 4 v i n = 2 . 7 v t o 7 v e n i n p u t b i a s c u r r e n t i e l _ t o 7 v v e n = 0 v , v i n = 2 . 7 v t o 7 v s h u t d o w n o u t p u t v o l t a g e v o , s d u a q u i e s c e n t c u r r e n t q 1 1 3 0 0 u i n o u t _ 2 . 8 v < v ( t ) v o = v % m v _ _ _ _ 4 0 0 3 0 0 o u t o u t p a r a m e t e r s y m b o l m a x . t y p . c o n d i t i o n m i n . u n i t o u t p u t v o l t a g e o u t p u t c u r r e n t c u r r e n t l i m i t d r o p o u t v o l t a g e v o u t i o i l i m v d r o p o u t - 1 . 5 % 3 0 0 3 0 0 - 1 v m a v o > 1 . 2 v v i n = v o u t ( t ) + 2 v , 1 o = 1 m a v i n = v o u t ( t ) + 2 v , v o u t _ _ _ _ v o u t ( t ) 2 . 0 v 2 . 0 v v o u t ( t ) 2 . 8 v 1 ?? v o u t ( e ) * 0 . 9 6 ( e ) v o u t 2 ( e ) 1 . 5 % 4 5 0 m a l o a d r e g u l a t i o n r e g l o a d 0 . 2 v i n = v o u t ( t ) + 2 v , i o = 1 m a t o 3 0 0 m a 1 . 2 v _ i o = 3 0 0 m a ( e ) - 2 % < - 2 . 5 % 2 . 5 % v i n = v o u t ( t ) + 2 v , 1 o = 3 0 0 m a v i n = v o u t ( t ) + 2 v , 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 t a = 2 5 unless otherwise noted o c h t t p : / / w w w . s e c o s g m b h . c o m / o c) power dissipation ( input voltage output current output voltage operating ambient temperature junction temperature parameter symbo l ratings unit v ma v c mw v in i out tj max. 8 p d /(v in -v o ) -40~+125 1.5~5.0 -40~+85 380 o max. junction temperature t=100 eds classification v out topr tj p d 150 b c o c o a b s o l u t e m a x i m u m r a t i n g s s q21 23 c m o s p o s i t i v e v o l t a g e r e g u l a t o r e l e k t r o n i s c h e b a u e l e m e n t e 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 7
01-jun-2002 rev. a page 3 of 7 h t t p : / / w w w .s e c o sg m b h .c o m/ a n y c ha n g i n g o f s pe c if i c a t i o n w ill no t b e i n f o r m ed i nd i v i dual e l e k t r o n i s c h e b a u e l e m e n t e s q 2 1 2 3 - 1 5 p a r t n u m b e r m a r k i n g o u t p u t v o l t a g e p a r t n u m b e r m a r k i n g o u t p u t v o l t a g e s q 2 1 2 3 - 2 5 s q 2 1 2 3 - 2 8 s q 2 1 2 3 - 3 0 s q 2 1 2 3 - 3 3 s q 2 1 2 3 - 3 5 s q 2 1 2 3 - 3 7 s q 2 1 2 3 - 5 0 3 b 1 5 2 1 . 5 v 2 . 5 v 2 . 8 v 3 . 0 v 3 . 3 v 3 . 5 v 3 . 7 v 5 . 0 v s q 2 1 2 3 - 1 8 s q 2 1 2 3 - 2 7 s q 2 1 2 3 - 2 9 s q 2 1 2 3 - 3 1 s q 2 1 2 3 - 3 4 s q 2 1 2 3 - 3 6 s q 2 1 2 3 - 3 8 s q 2 1 2 3 - 2 h 1 . 8 v 2 . 7 v 2 . 9 v 3 . 1 v 3 . 4 v 3 . 6 v 3 . 8 v 2 . 8 5 v x x x x 3 b 2 5 2 x x x x 3 b 2 8 2 x x x x 3 b 3 0 2 x x x x 3 b 3 3 2 x x x x 3 b 3 5 2 x x x x 3 b 3 7 2 x x x x 3 b 5 0 2 x x x x 3 b 1 8 2 x x x x 3 b 2 7 2 x x x x 3 b 2 9 2 x x x x 3 b 3 1 2 x x x x 3 b 3 4 2 x x x x 3 b 3 6 2 x x x x 3 b 3 8 2 x x x x 3 b 2 h 2 x x x x o r d e r i n g i n f o r m a t i o n ( c o n t d . ) s q 2 1 2 3 c m o s p o s i t i v e v o l t a g e r e g u l a t o r c h a r a c t e r i s t i c s c u r v e n o t e 1 : v o u t ( e) = ef f e c t i v e o u t p u t v o l t a g e ( i . e . t h e o u t p u t v o l t a g e w h e n " v o u t (t ) + 1 . 0 v" i s p r o v i d e d a t t h e v i n p i n w h i l e m a i n t a i n i n g a c e rt a i n i o u t v a l u e ). 2 : v o u t (t ) = s p e c i f i e d o u t p u t v o l t a g e 3 : v i n ( m i n ) = v o u t + v d r o p o u t 4 : t o p r e v e n t t h e s h o r t c i rc u i t c u rr e n t p r o t e c t i o n f e a t u r e f ro m b e i n g p r e m a t u r e l y a c t i v a t e d , t h e i n p u t v o l t a g e m u s t b e a p p l i e d b e f o r e a c u rr e n t s o u rc e l o a d i s a p p l i e d .
e l ek tr on isch e b a u e lemen te 01 -jun-2002 rev. a page 4 of 7 http://www.secosgmbh.com/ any changing of specification will not be informed individual s q 21 2 3 cmos positive voltage regulator
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 5 of 7 s q 21 2 3 cmos positive voltage regulator
0 1 - j u n - 2 0 0 2 r e v . a p a g e 6 o f 7 h t t p : / / w w w .s e c o sg m b h .c o m/ a n y c ha n g i n g o f s pe c if i c a t i o n w ill no t b e i n f o r m ed i nd i v i dual e l e k t r o n i s c h e b a u e l e m e n t e s q 21 2 3 cmos positive voltage regulator
01-jun-2002 rev. a page 7of 7 ht t p : / /www.se cosgmb h.com/ any c ha nging of s pe c ificat ion will no t be inf ormed individual e l e k t r o n i s c h e b a u e l e m e n t e s q 21 2 3 cmos positive voltage regulator d e t a i l e d d e s c r i p t i o n t h e s q 2 1 2 3 s e r i e s o f c o m s r e g u l a t o r s c o n t a i n a p m o s p a s s t r a n s i s t o r , v o l t a g e r e f e r e n c e , e r r o r a m p l i f i e r , o v e r - c u r r e n t p r o t e c t i o n a n d t h e r m a l s h u t d o w n . t h e p - c h a n n e l p a s s t r a n s i s t o r r e c e i v e s d a t a f r o m t h e e r r o r a m p l i f i e r , o v e r - c u r r e n t s h u t d o w n , a n d t h e r m a l p r o t e c t i o n c i r c u i t s . d u r i n g n o r m a l o p e r a t i o n , t h e e r r o r amplifier compares the output voltage to a precision reference. over-current and thermal shut- do wn circuits become active when the junction temperature exceeds150 c, or the current exceeds 300ma. during thermal shutdown, t h e o u t p u t v o l t a g e r e m a i n s l o w . n o r m a l o p e r a t i o n i s r e s t o r e d 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 d r o p s b e l o w 1 2 0 c . t h e s q 2 1 2 3 s w i t c h e s f r o m v o l t a g e m o d e t o c u r r e n t m o d e w h e n t h e l o a d e x c e e d s t h e r a t e d o u t p u t c u r r e n t . t h i s p r e v e n t s o v e r - s t r e s s . t h e s q 2 1 2 3 a l s o i n - o o c o r p o r a t e s c u r r e n t f o l d - b a c k t o r e d u c e p o w e r d i s s i p a t i o n w h e n t h e o u t p u t i s s h o r t c i r c u i t e d . t h i s f e a t u r e b e c o m e s a c t i v e w h e n t h e o u t p u t d r o p s b e l o w 0 . 8 v o l t s , a n d r e d u c e s t h e c u r r e n t f l o w b y 6 5 % . f u l l c u r r e n t i s r e s t o r e d w h e n t h e v o l t a g e e x c e e d s 0 . 8 v o l t s . external capacitors t h e s q 2 1 2 3 is stable with an output capacitance to ground of 2.2uf or greater. ceramic capacitors have the lowest esr, and will offer t h e best ac performance. conversely, aluminum elertrolytic capacitors exhibit the highest esr, resulting in the poorest ac response. unfortunately, large value ceramic capacitors are comparatively expensive. one option is to parallel a 0.1 uf ceramic capacitor with a 10 uf aluminum electrolytic. the benefit is low esr, high capacitance, and low overall cost. a second capacitor is recommended bet ween the input and ground to stabilize vin. the input capacitor should be at least 0.1uf to have a beneficial effect. a third capacitor can be connected between the by-pass pin and gnd. this capacitor can be a low cost polyester film variety between the value of 0.001 ~0.01 uf. a large capacitor improves the ac ripple rejection, but also makes the output come up slowly. this "soft" turn-on is desirable in some applications to limit turn-on surges. all capacitors should be placed in close proximity to the pins. a "quiet" ground termination is desirable . the can be achieved with a "star" connection. enable the enable pin normally floats high. when actively, pulled low, the pmos pass transistor shuts off, and all internal circuits are powered down. in this state, the quiescent current is less than 1ua. this pin behaves much like an electronic switch.
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