power management 1 www.semtech.com SC4201 multi-phase link controller features revision 3, november 2002 the SC4201 is a multi-phase link controller, ideal for iso- lated and non-isolated applications. its frequency of op- eration can be programmed in excess of 1.5mhz and can be easily synchronized to an external faster frequency. the SC4201 output frequencies can be set to 2/4 or 3 phase operation. a single pin can either set a 4 phase operation (each phase is 90 degrees apart) or 3 phase operation (120 degrees apart). multi-phase operation of multiple primary or secondary controllers reduces input/output ripple, the number of components required for filtering, and noise due to fre- quency beating generated by multiple free running oscil- lators. the SC4201 is available in the msop-8 surface mount package. ? low cost/small size ? programmable frequency up to 2mhz, each phase ? synchronized to faster frequency ? programmable 2/4 or 3 phase operation ? telecom distributed power architectures ? multi-phase operation of power supplies ? multi-phase operation of switching regulators typical application circuit description applications rt 1 sync 2 vdd 3 d 7 gnd 8 b 5 c 6 a 4 u1 SC4201 ph a ph b ph c ph d sync r1 5k c1 0.1 +3 to 6v vdd for 3 phase
2 ? 2002 semtech corp. www.semtech.com power management SC4201 r e t e m a r a pl o b m y ss t i m i ls t i n u e g a t l o v y l p p u sv n i 7v g n i t a r e p oe g n a r e r u t a r e p m e t t n e i b m at a 5 0 1 + o t 0 4 -c g n i t a r e p oe g n a r e r u t a r e p m e t n o i t c n u jt j 5 2 1 o t 0 4 -c 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 3 +c t n e i b m a o t n o i t c n u j e c n a d e p m i l a m r e h t a j 6 0 2w / c r e t e m a r a pl o b m y ss n o i t i d n o cn i mp y tx a ms t i n u e g a t l o v y l p p u s v d d 36v t n e r r u c y l p p u si d d v d d r , v 6 = t k 0 2 =2a m d l o h s e r h t t r a t s d d v 0 7 . 20 1 . 3v s i s e r e t s y h o l v u d d v 0 0 1v m y c n e u q e r f t u p t u of t u o v d d v 6 =1 . 02z h m y c a r u c c a y c n e u q e r f t u p t u ov d d v 6 =0 1% d l o h s e r h t t u p n i c n y sv c n y s 3 / d d vv y c a r u c c a e s a h pv d d v 6 =1% e m i t e s i r p / o t r c t u o f p 0 2 =0 2s n e m i t l l a f p / ot f c t u o f p 0 2 = 0 2s n t u p t u ov t u o v d d v n o i t a r u d t u p t u ot p ) 1 (s n unless specified: t a = 25c, absolute maximum ratings electrical characteristics exceeding the specifications below may result in permanent damage to the device, or device malfunction. operation outside of th e parameters specified in the electrical characteristics section is not implied. notes: (1) where t out = output signal period of individual phase. n = 3 for 3 phase operation, n = 4 for 2/4 phase operation. (2) this device is esd sensitive. use of standard esd handling is required. yyww = datecode (example: 0012) xxxx = semtech lot # (example: e901 xxxx = 01-1) marking information n t t out p =
3 ? 2002 semtech corp. www.semtech.com power management SC4201 top view (msop-8) r e b m u n t r a p ) 1 ( e g a k c a p r t s m i 1 0 2 4 c s8 - p o s m b v e 1 0 2 4 c sd r a o b n o i t a u l a v e note: (1) only available in tape and reel packaging. a reel contains 2500 devices. pin descriptions block diagram pin configuration ordering information n i pe m a n n i pn o i t c n u f n i p 1t r n a c r r o f s e u l a v . d n u o r g o t t r m o r f r r o t s i s e r g n i t c e n n o c y b d e r u g i f n o c s i y c n e u q e r f r o t a l l i c s o . s e i c n e u q e r f t u p t u o e s a h p 4 r o e s a h p 3 d e r i s e d e d i v o r p o t d e t c e l e s e b 2d d v. e c i v e d e h t r o f n o i t c e n n o c t u p n i r e w o p e h t 3c n y s d e d n u o r g e b d l u o h s c n y s . v 5 . 1 f o d l o h s e r h t a h t i w t u p n i d e r e g g i r t e g d e e v i t i s o p a s i c n y s n a h t r e h g i h y c n e u q e r f h t i w k c o l c n o i t a z i n o r h c n y s l a n r e t x e n a o t d e t c e n n o c r o d e r i u q e r t o n n e h w . ) k c o l c l a n r e t n i o t t c e p s e r h t i w ( y c n e u q e r f r o t a l l i c s o d r a o b n o e h t 4a . " a " e s a h p . k c o l c t u p t u o l e v e l c i g o l 5b . " b " e s a h p . k c o l c t u p t u o l e v e l c i g o l 6c . " c " e s a h p . k c o l c t u p t u o l e v e l c i g o l 7d e s a h p 2 / e s a h p 4 n o i t a r e p o t l u a f e d . n i p n o i t c e l e s e s a h p d n a k c o l c t u p t u o l e v e l c i g o l . e s a h p f o t u o 0 2 1 c d n a b , a h g u o r h t n o i t a r e p o e s a h p 3 t c e l e s o t d d v o t d e i t . ) 0 8 1 / 0 9 ( 8d n g. s n o i t c n u f l l a r o f d n u o r g r e w o p d n a d n u o r g e c n e r e f e r [] } { e phas / ) rt x pf 15 /( 25 . 1 f out
4 ? 2002 semtech corp. www.semtech.com power management SC4201 application information pwm = fsw l c sync pwm = fsw l c sync pwm = fsw l c sync pwm = fsw l c sync ph a ph b ph c ph d SC4201 v sync rt gnd dd vout1 vout 4 vout 2 vout 3 +3 to 6v optional 3 or 2/4 phases diagram in figure 1 shows multi-phase operation of several power converters with fixed switching frequency fsw. figure 1
5 ? 2002 semtech corp. www.semtech.com power management SC4201 pwm = fsw l sync pwm = fsw l c sync pwm = fsw l sync pwm = fsw l sync ph a ph b ph c ph d SC4201 v sync rt gnd dd vout +3 to 6v optional 3 or 2/4 phases application information (cont.) diagram in figure 2 demonstrates a multi-phase operation of a single power supply with current sharing through the individual phases and with fixed switching frequency fsw. figure 2
6 ? 2002 semtech corp. www.semtech.com power management SC4201 l l c l l ph a ph b ph c ph d SC4201 v sync rt gnd dd vout +3 to 6v optional 3 or 2/4 phases fsw control pwm fsw sync ~ pwm fsw sync ~ pwm fsw sync ~ pwm fsw sync ~ application information (cont.) diagram in figure 3 assumes variable switching frequency fsw, e.g. resonant power converters. this circuit will require additional ?fsw control? block, which is a task for a power designer. figure 3
7 ? 2002 semtech corp. www.semtech.com power management SC4201 l l c l l ph a ph b ph c ph d SC4201 - a v sync rt gnd dd vout +3 to 6v optional 3 or 2/4 phases fsw control pwm fsw sync ~ pwm fsw sync ~ pwm fsw sync ~ pwm fsw sync ~ ph a ph b ph c ph d SC4201 - b v sync rt gnd dd +3 to 6v power section of choice time delay (optional) application information (cont.) diagram in figure 4 demonstrates a synchronous operation of two (or more) SC4201 controllers. if the ?time delay? circuit is to be employed then 6-phase, 8-phase and other configurations become possible. figure 4
8 ? 2002 semtech corp. www.semtech.com power management SC4201 evaluation board schematic a out b out c out d out sync r2 100k +3 to 6v c3 22pf c4 22pf c5 22pf c6 22pf j1 r1 15k r3 1k c2 0.1 c1 1.0 rt 1 vdd 2 sync 3 d 7 gnd 8 b 5 c 6 a 4 u1 SC4201 run - sync 3 phase - 4 phase top view layout
9 ? 2002 semtech corp. www.semtech.com power management SC4201 semtech corporation power management products division 200 flynn road, camarillo, ca 93012 phone: (805)498-2111 fax (805)498-3804 land pattern - msop-8 outline drawing - msop-8 contact information
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