features greater than 90% efficiency adjustable output voltage up to 24v internal 24v power mosfet 520khz frequency built-in over-voltage protection (ovp) open protection programmable soft-start function thermal shutdown peak current 3a,4.5a,5.5a s under-voltage-lockout over-current protection sop-8(ep) package tft lcd monitors battery-powered equipment set-top boxes dsl and cable modems and routers the utilizes simple ex ternal loop compensation allowing optimization between component size, cost, and ac performance across a wide range of applications. additional functions include an externally programmable soft-start function for easy inrush current control, internal over-voltage pr otection (ovp) ,c ycle-by- cyc le current limit protection, under voltage lock-out and thermal shutdown. the pam242x is available in the small sop-8(ep) package. n n n applications general description n n the pam242x devices are high-performance,fixed frequency, current-mode pwm step-up dc/dc c o n v e r t e r t h a t i n c o r p o r a t e i n t e r n a l p o w e r mosfets. the pam242x includes an integrated power mosfet that supports peak currents of up to 3a/4.5a/5.5a. pam2 42x n n n n n n n n n n n typical application PAM2421,pam2422,pam2423 3a,4.5a,5.5a pwm step-up dc/dc converter 1 www.poweranalog.com , power analog microelectronics inc 02/2012 rev1.1 pam242x agnd vin sw ss comp pgnd en fb c3 l1 6.8 h 1 f ss34 c2 10 f c6 47p f r3 51k c7 2.2n f c8 10n f r1 r2 c4 10uf vin vout 3.6v~5.5v 12v/800ma 85k 10k c1 470 f c5 470uf
block diagram 2 www.poweranalog.com , power analog microelectronics inc 02/2012 rev1.1 pin configuration & marking information pcn: product code of pam242x xxx: internal code v: voltage code y: year w: week top view sop-8(ep) 1 2 3 4 5 6 7 8 pgnd vin en comp sw ss fb agnd PAM2421,pam2422,pam2423 3a,4.5a,5.5a pwm step-up dc/dc converter
pin descriptions p i n n u m b e r n a m e f u n c t i o n 1 p g n d p o w e r g r o u n d 2 i n s u p p l y i n p u t . 3 e n e n a b l e c o n t r o l . c o n n e c t t o a l o g i c h i g h l e v e l t o e n a b l e t h e i c . c o n n e c t t o a l o g i c l o w l e v e l t o d i s a b l e t h e i c . w h e n u n u s e d , c o n n e c t e n p i n t o i n ( d o n o t l e a v e p i n f l o a t i n g ) . 4 c o m p e r r o r a m p l i f i e r c o m p e n s a t i o n n o d e . 5 a g n d a n a l o g g r o u n d 6 f b f e e d b a c k i n p u t . c o n n e c t t h i s p i n a r e s i s t o r d i v i d e r f r o m t h e o u t p u t t o s e t t h e o u t p u t v o l t a g e . f b i s r e g u l a t e d t o 1 . 2 6 2 v . 7 s s s o f t s t a r t c o n t r o l i n p u t . c o n n e c t a c a p a c i t o r f r o m t h i s p i n t o g r o u n d t o s e t s o f t - s t a r t t i m i n g d u r a t i o n . s s i s d i s c h a r g e d t o g r o u n d i n s h u t d o w n . s s m a y b e l e f t u n c o n n e c t e d i f s o f t s t a r t i s n o t d e s i r e d . 8 s w s w i t c h o u t p u t . c o n n e c t t h i s p i n t o t h e i n d u c t o r a n d t h e s c h o t t k y d i o d e . t o m i n i m i z e e m i , m i n i m i z e t h e p c b t r a c e p a t h b e t w e e n t h i s p i n a n d t h e i n p u t b y p a s s c a p a c i t o r . e x p o s e d p a d c o n n e c t e d t o g o u n d 3 absolute maximum ratings these are stress ratings only and functional operation is not implied exposure to absolute maximum ratings for prolonged time periods may affect device reliability all voltages are with respect to ground . . . sw to ground...... ............................. vin, en, fb, ss, comp to ground........................ ...................................................... ................................................... ......... .......... ?0.3v to 28v ?0.3v to 6.5v continuous sw current..............internally limited operating temperature range............................. ?40 c to 150 c storage temperature range ?55 c to 150 c lead temperature (soldering, 10 sec) 300 c ? ? ? ? ? recommended operating conditions junction temperature 40 to 125 - ................... ..................... - ambient temperature 40 to 85 thermal information p a r a m e t e r p a c k a g e s y m b o l m a x i m u m u n i t t h e r m 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 ) s o p - 8 ( e p ) j c 7 5 t h e r m 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 ) s o p - 8 ( e p ) j a 1 8 0 / w , power analog microelectronics inc www.poweranalog.com 02/2012 rev1.1 PAM2421,pam2422,pam2423 3a,4.5a,5.5a pwm step-up dc/dc converter
p a r a m e t e r c o n d i t i o n s m i n t y p m a x u n i t i n p u t v o l t a g e 2 . 7 5 . 5 v u n d e r v o l t a g e l o c k o u t t h r e s h o l d v i n r i s i n g 2 . 5 v u n d e r v o l t a g e l o c k o u t h y s t e r e s i s 2 0 0 m v v f b = 1 . 4 v , n o t s w i t c h i n g 0 . 2 5 0 . 3 5 q u i e s c e n t s u p p l y c u r r e n t v f b = 1 . 0 v , s w i t c h i n g 3 5 m a s u p p l y c u r r e n t i n s h u t d o w n e n = g r o u n d 0 . 1 1 u a s w i t c h i n g f r e q u e n c y 5 2 0 k h z m a x i m u m d u t y c y c l e 8 5 % f b f e e d b a c k v o l t a g e 1 . 2 3 7 1 . 2 6 2 1 . 2 8 7 v f b i n p u t c u r r e n t 0 8 0 n a f b v o l t a g e l i n e r e g u l a t i o n v f b f r o m 2 . 7 v t o 5 . 5 v 0 . 0 5 0 . 1 5 % / v p a m 2 4 2 1 3 p a m 2 4 2 2 4 . 5 s w i t c h c u r r e n t l i m i t p a m 2 4 2 3 v i n = 3 . 2 v d u t y c y c l e = 7 0 % 5 . 5 a p a m 2 4 2 1 1 3 0 p a m 2 4 2 2 1 0 0 s w i t c h o n r e s i s t a n c e p a m 2 4 2 3 7 0 m s w i t c h l e a k a g e c u r r e n t v s w = 1 0 v , e n = g r o u n d 1 5 u a s o f t s t a r t p i n b i a s c u r r e n t v s s = 1 . 2 v 2 4 . 5 7 u a l o g i c h i g h t h r e s h o l d e n p i n 1 . 4 v l o g i c l o w t h r e s h o l d e n p i n 0 . 4 v e n p u l l d o w n r e s i s t o r 1 m t h e r m a l s h u t d o w n t e m p e r a t u r e 1 6 0 t h e r m a l s h u t d o w n h y s t e r e s i s 4 0 electrical characteristic at t =25 a ? c ,v =v =5v,,unless otherwise specified. in en 4 , power analog microelectronics inc www.poweranalog.com 02/2012 rev1.1 PAM2421,pam2422,pam2423 3a,4.5a,5.5a pwm step-up dc/dc converter
typical operating characteristics at t =25 a ? c ,v =v =5v,v =0v,unless otherwise specified. in en freq 5 , power analog microelectronics inc www.poweranalog.com 02/2012 rev1.1 efficiency vs input voltage (vo=12v) efficiency vs input voltage (vo=15v) efficiency vs output current (vo=12v) efficiency vs output current (vo=15v) 0 % 1 0 % 2 0 % 3 0 % 4 0 % 5 0 % 6 0 % 7 0 % 8 0 % 9 0 % 1 0 0 % 1 1 0 1 0 0 1 0 0 0 l o a d c u r r e n t ( m a ) v i n = 3 . 6 v v i n = 4 . 2 v v i n = 5 v 0 % 1 0 % 2 0 % 3 0 % 4 0 % 5 0 % 6 0 % 7 0 % 8 0 % 9 0 % 1 0 0 % 1 1 0 1 0 0 1 0 0 0 l o a d c u r r e n t ( m a ) v i n = 3 . 6 v v i n = 4 . 2 v v i n = 5 v 0 % 1 0 % 2 0 % 3 0 % 4 0 % 5 0 % 6 0 % 7 0 % 8 0 % 9 0 % 1 0 0 % 3 3 . 5 4 4 . 5 5 5 . 5 i n p u t v o l t a g e ( v ) 1 m a 1 0 m a 1 0 0 m a 5 0 0 m a 1 a 0 % 1 0 % 2 0 % 3 0 % 4 0 % 5 0 % 6 0 % 7 0 % 8 0 % 9 0 % 1 0 0 % 3 3 . 5 4 4 . 5 5 5 . 5 i n p u t v o l t a g e ( v ) 1 m a 1 0 m a 1 0 0 m a 5 0 0 m a PAM2421,pam2422,pam2423 3a,4.5a,5.5a pwm step-up dc/dc converter efficiency vs output current (vo=5v) efficiency vs input voltage (vo=5v) 0 % 1 0 % 2 0 % 3 0 % 4 0 % 5 0 % 6 0 % 7 0 % 8 0 % 9 0 % 1 0 0 % 1 1 0 1 0 0 1 0 0 0 1 0 0 0 0 o u t p u t c u r r e n t ( m a ) v i n = 2 . 7 v v i n = 3 . 6 v v i n = 4 . 2 v 0 % 1 0 % 2 0 % 3 0 % 4 0 % 5 0 % 6 0 % 7 0 % 8 0 % 9 0 % 1 0 0 % 2 . 5 3 3 . 5 4 4 . 5 5 i n p u t v o l t a g e ( v ) i o = 1 m a i o = 1 0 m a i o = 1 0 0 m a i o = 5 0 0 m a i o = 1 a
typical operating characteristics at t =25 a ? c ,v =v =5v,v =0v,unless otherwise specified. in en freq 6 , power analog microelectronics inc www.poweranalog.com 02/2012 rev1.1 output voltage vs output current (vo=12v) output voltage vs output current (vo=15v) PAM2421,pam2422,pam2423 3a,4.5a,5.5a pwm step-up dc/dc converter 1 0 1 0 . 5 1 1 1 1 . 5 1 2 1 2 . 5 0 2 0 0 4 0 0 6 0 0 8 0 0 1 0 0 0 l o a d c u r r e n t ( m a ) v i n = 4 . 2 v v i n = 5 v 1 3 1 3 . 5 1 4 1 4 . 5 1 5 1 5 . 5 0 2 0 0 4 0 0 6 0 0 8 0 0 1 0 0 0 l o a d c u r r e n t ( m a ) v i n = 3 . 6 v v i n = 4 . 2 v v i n = 5 v quiescent current (v =1.4v) fb quiescent current (v =1.0v) fb 0 0 . 0 5 0 . 1 0 . 1 5 0 . 2 0 . 2 5 2 3 4 5 6 i n p u t v o l t a g e ( v ) 0 0 . 5 1 1 . 5 2 2 . 5 3 3 . 5 4 2 3 4 5 6 i n p u t v o l t a g e ( v )
7 application information the pam242x are highly efficient step -up dc/dc converters that employ a currentmode,fixed f r e q u e n c y p u l s e - w i d t h m o d u l a t i o n ( p w m ) a r c h i t e c t u r e w i t h e x c e l l e n t l i n e a n d l o a d regulation.the operate at constant switching frequency under medium to high load current conditions. at light loads, these devices operate in a pulse-skipping mode in order to improve light-load efficiency. the both offer a programmable soft- start function which minimizes inrush current d u r i n g s t a r t u p . t h e s o f t - s t a r t p e r i o d i s programmed by connecting a 10nf capacitor between ss and ground. operation of the soft- start function is as follows: when the ic is disabled, ss is actively discharged to ground. upon enabling the ic, css is charged with a 4.5 a current so that the voltage at ss increases in a controlled manner. the peak inductor current is limited by the voltage at ss, so that the input current is limited until the soft-start period expires, and the regulator can achieve its full output current rating. the bo th feature external adjustable output voltages of up to 24v. to program the output voltage, simply connect a resistive voltage divider between the output, fb, and g nd, wi th r es istor s s et acc ordi ng to the following equation: where vfb is 1.262v. for optimal performance, the rectifier should be a schottky rectifier that is rated to handle both the output voltage as well as the peak switch current. the features internal automatic over- voltage protection, when feedback voltage is higher than 115%. once the outputs achieve regulation, if the voltage at fb falls below 0.2v the controller will automatically disable, preventing the controller f r o m r u n n i n g o p e n - l o o p a n d p o t e n t i a l l y damaging the ic and load. drive en low to disable the ic and reduce the su pply c urr ent to j ust 0.1 a . as wi th al l nonsynchronous step-up dc/dc converters, the external schottky diode provides a dc path from the input to the output in shutdown. as a result, the output drops to one diode voltage drop below the input in shutd own. the both feature integrated thermal o v e r l o a d p r o t e c t i o n . b o t h d e v i c e s a r e automatically disabled when their junction temperatures exceed 160c, and automatically re-enable when the die temperature decreases by 40c. pam242x pam242x pam242x pam242x pam242x soft-start setting the output voltage rectifier selection over voltage protection open protection shutdown thermal shutdown , power analog microelectronics inc www.poweranalog.com 02/2012 rev1.1 PAM2421,pam2422,pam2423 3a,4.5a,5.5a pwm step-up dc/dc converter
ordering information 8 , power analog microelectronics inc www.poweranalog.com 02/2012 rev1.1 pam 242x x x x xxx x output voltage number of pins package type pin configuration shipping package p a r t n u m b e r p e a k c u r r e n t p a c k a g e t y p e s h i p p i n g p a c k a g e p a m 2 4 2 1 a e c a d j r 3 a s o p - 8 ( e p ) 2 , 5 0 0 u n i t s / t a p e & r e e l p a m 2 4 2 2 a e c a d j r 4 . 5 a s o p - 8 ( e p ) 2 , 5 0 0 u n i t s / t a p e & r e e l p a m 2 4 2 3 a e c a d j r 5 . 5 a s o p - 8 ( e p ) 2 , 5 0 0 u n i t s / t a p e & r e e l PAM2421,pam2422,pam2423 3a,4.5a,5.5a pwm step-up dc/dc converter p i n c o n f i g u r a t i o n p a c k a g e t y p e n u m b e r o f p i n s o u t p u t v o l t a g e a t y p e e : s o p - 8 ( e p ) c : 8 a d j : a d j u s t a b l e
outline dimension 9 , power analog microelectronics inc www.poweranalog.com 02/2012 rev1.1 sop-8(ep) PAM2421,pam2422,pam2423 3a,4.5a,5.5a pwm step-up dc/dc converter
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