power management 1 www.semtech.com SC1410A constant voltage/constant current battery charger features applications revision feb 2001 preliminary typical application circuits description the SC1410A is designed to provide a simple, fast charg- ing solution for rechargeable batteries that require con- stant-current and/or constant voltage charging, including nickel-cadmium (nicd), nickel-metal-hydride (nimh) and lithium-ion (li-ion). with a voltage reference accuracy of 0.5% the SC1410A satisfies the tight constant-voltage charging requirements of lithium cells. the SC1410A simplifies battery charger design by inte- grating a high efficiency pwm with an internal 1.5a switch and 0.1ohm current sense resistor, while the 500khz switching frequency allows a very small inductor to be used. only one external resistor is required to program the full 1.5a charging current to within 5% accuracy. charging circuits for batteries ranging from 2v to 18v are easily implemented using the SC1410A. no ground sens- ing of current is required, allowing the battery?s negative terminal to be connected directly to ground. no blocking diode is required between the ic and the battery since the SC1410A enters sleep mode and consumes only 3a when the ac adapter is unplugged. other features include soft start, overvoltage protection, and a shutdown pin. the SC1410A is available in a 16 pin qsop package. u charges nicd, nimh and lithium-lon batteries u high efficiency current mode with 1.5a internal switch and sense resistor u 3% typical charging current accuracy u precision 0.5% voltage reference for voltage mode charging or over voltage protection u current sensing can be either terminal of battery u low reverse battery drain current: 3a u charging current soft start u shutdown control u 500khz switching uses small inductor u chargers for nicd, nimh and lithium batteries u step down switching regulator with precision adjustable current limit figure 2: charging lithium batteries 1uf 6.19k 240k 0.25% 100k 0.25% nds355n 22uf cout 11 to 18v 1k 1410 sch42 + 4.2v 1n5819 0.1uf 0.22uf 33uh 300 1n4148 + 4.2v 10uf cin SC1410A sw vcc vc prog sense boost bat gnd ovp 1n5819 figure 1: 500khz li-lon cell phone charger SC1410A sw vcc vc prog sense boost bat gnd ovp 10uh 1k 300 8.2 to 18v nds355n 22uf cout 1n4148 1410 sch41 70.6k 0.25% 1n5819 + 4.2v 1uf 0.22uf 10uf cin 1n5819 0.1uf 6.19k 100k 0.25%
2 ? 2000 semtech corp. www.semtech.com power management SC1410A preliminary electrical characteristics absolute maximum ratings r e t e m a r a pl o b m y sm u m i x a ms t i n u e g a t l o v y l p p u sv x a m 0 2v d n g o t t c e p s e r h t i w e g a t l o v h c t i w s 3 -v d n g o t t c e p s e r h t i w e g a t l o v n i p t s o o b 5 - / 4 2 +v e g a t l o v n i p p v o , g o r p , c v 8v i t a b ) e g a r e v a ( 5 . 1a e s a c o t n o i t c n u j , e c n a t s i s e r l a m r e h t q c j w / c t n e i b m a o t n o i t c n u j , e c n a t s i s e r l a m r e h t q c j w / c e g n a r e r u t a r e p m e t g n i t a r e p ot a 0 7 o t 0c e g n a r e r u t a r e p m e t e g a r o t st g t s 0 5 1 + o t 5 6 -c . c e s 0 1 ) g n i r e d l o s ( e r u t a r e p m e t d a e lt d a e l 0 0 3c unless specified: vcc = 16v, v bat = 8v; i bat =0 r e t e m a r a ps n o i t i d n o cn i mp y tx a ms t i n u t n e r r u c y l p p u sv g o r p c c v , v 7 . 2 = 3 ? 2000 semtech corp. www.semtech.com power management SC1410A electrical characteristics (cont.) unless specified: v cc = 16v, v bat = 8v, v max (maximum operating v cc ) r e t e m a r a ps n o i t i d n o cn i mp y tx a ms t i n u ) t a b , e s n e s ( s t u p n i r e i f i l m a e s n e s t n e r r u c ) 1 s r ( e c n a t s i s e r e s n e s 8 0 . 02 1 . 0 w t a b o t e s n e s m o r f e c n a t s i s e r l a t o t 2 . 05 2 . 0 w t n e r r u c s a i b t a bv 3 . 0 < c v v 6 . 0 > c v 0 0 2 - 0 0 7 5 7 3 - 0 0 3 1 a ) w o l ( t i m i l e d o m n o m m o c t u p n i 5 2 . 0 -v ) h g i h ( t i m i l e d o m n o m m o c t u p n i 2 - c c vv e c n e r e f e r e g a t l o v e c n e r e f e rr g o r p h t i w p v o t a d e r u s a e m , k 8 2 . 3 = i g n i y l p p u s a v g o r p f f o h c t i w s d n a 8 4 4 . 25 6 4 . 22 8 4 . 2v e c n a r e l o t e g a t l o v e c n e r e f e rv 8 c c v c 0 , v 8 1 t j c 0 7 v 8 c c v c 0 , v 8 1 t j c 5 2 1 6 4 4 . 2 1 4 4 . 2 5 6 4 . 20 8 4 . 2 9 8 4 . 2 v r o t a l l i c s o y c n e u q e r f g n i h c t i w s 0 4 40 0 50 5 5z h k e l c y c y t u d m u m i x a m 7 7% ) 2 a c ( r e i f i l p m a t n e r r u c e c n a t c u d n o c s n a r tv c i , v 1 = c v a 1 =0 5 10 5 20 5 5o h m f f o h c t i w s r o f c v m u m i x a m 6 . 0v i c v ) n i p f o t u o ( t n e r r u cv c 3 v 6 . 00 0 1a ) a v ( r e i f i l p m a e g a t l o v e c n a t c u d n o c s n a r t a 0 0 5 o t a 0 0 1 m o r f t n e r r u c t u p t u o5 . 02 . 15 . 2o h m v 0 1 = c c v , t n e r r u c e c r u o s t u p t u ov g o r p v = p v o v = f e r v m 0 3 +3 . 1a m t n e r r u c s a i b t u p n i p v o t n e r r u c t u p t u o a v a m 5 7 . 0 t a0 50 5 1a n preliminary
4 ? 2000 semtech corp. www.semtech.com power management SC1410A preliminary pin configuration ordering information pin descriptions note: (1) only available in tape and reel packaging. a reel contains 2500 devices. e c i v e d ) 1 ( e g a k c a p r t s q c a 0 1 4 1 c s6 1 - p o s q r e b m u n n i pe m a n n i pn o i t c n u f n i p 6 1 , 9 , 8 , 1d n g e c n a m r o f r e p l a m r e h t m u m i t p o r o f e l d d a p h c a t t a e i d e h t o t d e s u f e r a s n i p d n u o r g e s e h t . a e r a r e p p o c b c p e g r a l o t s n i p e s e h t t c e n n o c 2w s. t u p t u o h c t i w s 3t s o o b e g a t l o v - n o w o l a o t r o t s i s n a r t n p n r e w o p h c t i w s e h t e v i r d d n a p a r t s t o o b o t d e s u s i n i p s i h t . n o i t a p i s s i d r e w o p w o l r o f 4d n g. n i p d n u o r g 5p v o . d e r i u q e r t o n f i d n u o r g , t u p t u o e g a t l o v t n a t s n o c r o f e d o n k c a b d e e f 1 1 , 6c n. s n i p e s e h t o t t c e n n o c t o n o d , n o i t c e n n o c o n 7e s n e s . y r e t t a b e h t f o l a n i m r e t r e h t i e t a e b n a c g n i s n e s . t u p n i 1 a c r e i f i l p m a t n e r r u c 0 1t a b. t u p n i 1 a c r e i f i l p m a t n e r r u c 2 1c v d n a v 7 . 0 t a s t r a t s g n i h c t i w s . m w p e d o m t n e r r u c e h t f o p o o l r e t n i e h t f o l a n g i s l o r t n o c t a f o r o t i c a p a c a . n o i t a r e p o l a m r o n n i t n e r r u c g n i g r a h c r e h g i h o t s d n o p s e r r o c c v r e h g i h n w o d t u h s o t . t r a t s t f o s f o e t a r e h t s l o r t n o c d n a e s i o n t u o s r e t l i f d n g o t f u 1 . 0 t s a e l . a u 0 3 s i t n e r r u c t u p t u o l a c i p y t . w o l n i p s i h t l l u p , g n i h c t i w s 3 1g o r p . n o i t a s n e p m o c p o o l m e t s y s r o f d n a t n e r r u c g n i g r a h c e h t g n i m m a r g o r p r o f s i n i p s i h t 4 11 c c v. p i h c e h t r o f y l p p u s 5 12 c c v. p i h c e h t r o f y l p p u s 1 2 3 4 5 6 7 8 gnd gnd top view (16 pin qsop) 13 12 14 15 16 11 10 9 vcc2 sw vcc1 boost prog gnd vc ovp nc nc bat sense gnd gnd
5 ? 2000 semtech corp. www.semtech.com power management SC1410A block diagram 1k vbat vc vsw rprog + - slope comp. sw iprog ibat + - shutdown qsw sense 60k vref 2.465v + - ca1 boost iprog 500khz oscillator + - ca2 r s q bat 0.7v vcc + - + - va rs1 + - cprog prog 1410 sch22 vcc = 500ua/a ovp
6 ? 2000 semtech corp. www.semtech.com power management SC1410A semtech corporation power management products division 652 mitchell rd., newbury park, ca 91320 phone: (805)498-2111 fax (805)498-3804 preliminary contact information outline drawing - qsop-16 land pattern -qsop-16 (drawing pending)
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