1 www.semtech.com sc4211 very low input /very low dropout 1 amp regulator with enable power management power management revision: november 06, 2008 the sc4211 is a high performance positive voltage regulator designed for use in applications requiring very low input voltage and very low dropout voltage at up to 1 amperes. it operates with a vin as low as 1.4v, with output voltage programmable as low as 0.5v. the sc4211 features ultra low dropout, ideal for applications where vout is very close to vin. additionally, the sc4211 has an enable pin to further reduce power dissipation while shutdown. the sc4211 provides excellent regula- tion over variations in line, load and temperature. the sc4211 is available in the soic-8-edp (exposed die pad) package. depending on how the fb pin is config- ured, the output voltage can be either externally adjusted or fixed to either 0.5v or 1v. ? input voltage as low as 1.4v ? 400mv dropout @ 1a ? adjustable output from 0.5v ? over current and over temperature protection ? enable pin ? 10a quiescent current in shutdown ? full industrial temperature range ? available in soic-8-edp lead-free package, fully weee and rohs compliant ? telecom/networking cards ? motherboards/peripheral cards ? industrial applications ? wireless infrastructure ? set top boxes ? medical equipment ? notebook computers ? battery powered systems volts r2 r2) (r1 0.5 vo + = description features applications typical application circuits c2 u1 sc4211 4 3 2 8 1 5 6 7 nc vin en gnd nc nc vo fb vo = 1v vin c1 enable c2 u1 4 3 2 8 1 5 6 7 nc vin en gnd nc nc vo fb vo = 0.5v vin c1 enable sc4211 enable c1 r2 vin r1 u1 sc4211 4 3 2 8 1 5 6 7 nc vin en gnd nc nc vo fb vo c2
2 ? 2007 semtech corp. www.semtech.com sc4211 power management 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. r e t e m a r a p l o b m y sx a ms t i n u d n g o t b f , o v , n e , n i v 7v n o i t a p i s s i d r e w o p p d d e t i m i l y l l a n r e t n iw 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 ) 1 ( a j 6 3w / c 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 ) 1 ( c j 5 . 5w / c e g n a r e r u t a r e p m e t t n e i b m a g n i t a r e p o t a 5 8 + o t 0 4 -c e g n a r e r u t a r e p m e t n o i t c n u j g n i t a r e p o t 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 s t g t s 0 5 1 + o t 5 6 -c ) s 0 3 o t s 0 1 ( e r u t a r e p m e t w o l f e r r i k a e p t p 0 6 2c ) l e d o m y d o b n a m u h ( g n i t a r d s e ) 2 ( v d s e 2v k r e t e m a r a pl o b m y ss n o i t i d n o c t s e tn i mp y tx a ms t i n u n i v e g n a r e g a t l o v y l p p u sv n i 0 4 . 10 . 6 v t n e r r u c t n e c s e i u qi q v n i i , v 3 . 3 = o a 0 = 3 a m v n i v , v 0 . 6 = n e v 0 =0 1 0 5 a o v e g a t l o v t u p t u o ) 1 ( v o v n i v = o i , v 5 . 0 + o a m 0 1 =% 2 -v o % 2 +v v , e g a t l o v d e x i f ( b f ) 0 = v 0 4 . 1 v n i i , v 0 . 6 o a m 0 1 = % 3 -% 3 + n o i t a l u g e r e n i l ) 1 ( g e r ) e n i l ( i o a m 0 1 =2 . 0 4 . 0 v / % n o i t a l u g e r d a o l ) 1 ( g e r ) d a o l ( i o a 1 o t a m 0 1 =5 . 0 5 . 1 v / % e g a t l o v t u o p o r d ) 2 ( ) 1 ( v o d i o a m 0 0 5 =0 0 10 5 2v m 0 0 3 unless specified: v en = v in , v fb = v o, v in = 1.40v to 6.0v, i o = 10 a to 1a. values in bold apply over the full operating temperature range. notes: (1) calculated from package in still air, mounted to 3? x 4.5?, 4 layer fr4 pcb with thermal vias under the exposed pad per jesd51 standards, (2) tested according to jedec standard jesd22-a114-b.
3 ? 2007 semtech corp. www.semtech.com sc4211 power management electrical characteristics (cont.) r e t e m a r a pl o b m y ss n o i t i d n o c t s e tn i mp y tx a ms t i n u ) . t n o c ( o v e g a t l o v t u o p o r d ) 2 ( ) 1 ( v o d i o a 1 = 0 0 20 0 4 v m 0 0 5 t n e r r u c d a o l m u m i n i m ) 3 ( i o v n i v = o v 5 . 0 + 0 1 a t i m i l t n e r r u c ) 4 ( i l c 1 . 1 5 . 1 0 . 2 a k c a b d e e f e g a t l o v e c n e r e f e r ) 1 ( v f e r v n i v , v 3 . 3 = b f v = t u o i , o a m 0 1 =5 9 4 . 05 . 05 0 5 . 0v i l l u f t u o v d n a , n i e g n a r 0 9 4 . 00 1 5 . 0 t n e r r u c n i p k c a b d e e f ) 4 ( i j d a v b f v = f e r 0 8 0 0 2 a n d l o h s e r h t n i p k c a b d e e f ) 5 ( v ) b f ( h t 5 0 . 0 6 1 . 0 0 4 . 0 v n e t n e r r u c n i p e l b a n ei n e v n e v , v 0 = n i v 3 . 3 =5 . 1 0 1 a d l o h s e r h t n i p e l b a n ev h i v n i v 3 . 3 = 6 . 1 v v l i v n i v 3 . 3 = 4 . 0 n o i t c e t o r p e r u t a r e p m e t r e v o l e v e l p i r t h g i ht i h 0 6 1c s i s e r e t s y ht t s y h 0 1c notes: (1) low duty cycle pulse testing with kelvin connections required. (2) v do = v in -v o when v o decreases by 1.5% of its nominal output voltage with v in = v o +0.8v. (3) required to maintain regulation. voltage set resistors r1 and r2 are usually utilized to meet this requirement. (4) guaranteed by design. (5) when v fb exceeds this threshold, the ?sense select? switch disconnects the internal feedback chain from the error amplifier and connects v fb instead. unless specified: v en = v in , v fb = v o, v in = 1.40v to 6.0v, i o = 10 a to 1a. values in bold apply over the full operating temperature range.
4 ? 2007 semtech corp. www.semtech.com sc4211 power management pin descriptions pin configuration ordering information r e b m u n t r a pe g a k c a pt ( e g n a r . p m e t j ) t r t s 1 1 2 4 c s ) 2 ( ) 1 ( p d e - 8 - c i o s5 2 1 + o t 0 4 - o c b v e 1 1 2 4 c sd r a o b n o i t a u l a v e notes: (1) only available in tape and reel packaging. a reel con- tains 2500 devices. (2) lead-free product. this product is fully weee and rohs compliant. top view soic-8-edp-2 vin nc nc nc en vo fb gnd 1 2 3 4 en nc 5 6 7 8 nc fb vo vin nc gnd gnd exposed die pad bottom view soic-8-edp-2 volts r2 r2) (r1 0.5 vo + = # n i pe m a n n i pn o i t p i c s e d n i p 2n e a o t t n e r r u c t n e c s e i u q e h t g n i c u d e r , f f o r o t a l u g e r e h t s n r u t v 4 . 0 w o l e b n i p s i h t g n i l l u p . t u p n i e l b a n e t o n f i n i v o t t c e n n o c . n e p o t f e l s i n i p s i h t f i d e l b a n e e b l l i w e c i v e d e h t . e u l a v g n i t a r e p o s t i f o n o i t c a r f . d e s u g n i e b 3n i v . v 5 . 5 d n a ) v 5 . 0 + o v ( n e e w t e b e b t s u m n i p s i h t o t t u p n i e h t , d a o l l l u f t a n o i t a l u g e r r o f . e g a t l o v t u p n i e h t t a h t e r u s n e o t n i p s i h t o t y l e s o l c d e c a l p e b d l u o h s e c n a t i c a p a c k l u b e g r a l a . v 4 . 1 = n i v m u m i n i m d e c a l p e b d l u o h s r o t i c a p a c c i m a r e c f u 7 . 4 f o m u m i n i m a o s l a . v 4 . 1 w o l e b g a s t o n s e o d y l p p u s t u p n i . n i p s i h t t a y l t c e r i d 6o v t a y l t c e r i d d e c a l p e b d l u o h s r o t i c a p a c f u 0 1 f o m u m i n i m a . e c i v e d e h t f o t u p t u o r e w o p e h t s i n i p e h t . n i p s i h t 7b f d e t c e n n o c f i . v 0 . 1 o t e g a t l o v t u p t u o e h t s t e s r e d i v i d r o t s i s e r l a n r e t n i n a , d e d n u o r g s i n i p s i h t n e h w t u p t u o e h t , d e s u e r a s r o t s i s e r k c a b d e e f l a n r e t x e f i . v 5 . 0 t a t e s e b l l i w e g a t l o v t u p t u o e h t , n i p o v e h t o t : ) 1 e g a p n o s t i u c r i c n o i t a c i l p p a e e s ( e b l l i w e g a t l o v 8d n g . n i p c i e h t t a r e h t e g o t d e t c e n n o c e b t s u m d a p e i d d e s o p x e e h t d n a n i p d n g e h t . d n u o r g e c n e r e f e r 5 , 4 , 1c n. n o i t c e n n o c o n l a m r e h t d a p d e t c e n n o c y l l a c i r t c e l e t o n . s a i v e l p i t l u m g n i s u e n a l p d n u o r g o t t c e n n o c . s e s o p r u p g n i k n i s t a e h r o f d a p . y l l a n r e t n i
5 ? 2007 semtech corp. www.semtech.com sc4211 power management block diagram marking information yyww = datecode (example: 0015) xxxxx = semtech lot no. (example: 00101) 1.5ua 8v 0.5v 0.5v 0.5v 0.5v 0.5v ref ref ref ref ref fb fb fb fb fb top view sc4211 yyww xxxxx
6 ? 2007 semtech corp. www.semtech.com sc4211 power management typical characteristics region of instability region of instability stable region region of instability region of instability stable region
7 ? 2007 semtech corp. www.semtech.com sc4211 power management enable: pulling this pin below 0.4v turns the regulator off, reducing the quiescent current to a fraction of its operating value. a pull up resistor up to 400kohms should be connected from this pin to the vin pin in application where supply voltages of vin < 1.9v is required. for ap- plications with higher voltages than 1.9v, en pin could be left open or connected to vin. thermal considerations the power dissipation in the sc4211 is approximately equal to the product of the output current and the input to output voltage differential: () o d i vout vin p ? ? the absolute worst-case dissipation is given by: () q(max) (max) o(max) (min) (max) d(max) i vin i vout vin p ? + ? ? = for a typical scenario, v in = 3.3v 5%, v out = 2.8v and i o = 1a, therefore: v in(max) = 3.465v, v out(min) = 2.744v and i q(max) = 1.75ma, thus p d(max) = .722w. using this figure, and assuming t a(max) = 70c, we can cal- culate the maximum thermal impedance allowable to main- tain t j 150c: () () c/w 110 .722 70 150 p t t r d(max) a(max) j(max) a)(max) th(j = ? = ? = ? this should be achievable for the soic-8-edp package using pcb copper area to aid in conducting the heat away, such as one square inch of copper connected to the ground pins of the device. internal ground/power planes and air flow will also assist in removing heat. for higher ambient temperatures it may be necessary to use additional cop- per area. introduction the sc4211 is intended for applications where high cur- rent capability and very low dropout voltage are required. it provides a very simple, low cost solution that uses very little pcb real estate. additional features include an en- able pin to allow for a very low power consumption standby mode, and a fully adjustable output. component selection input capacitor: a large bulk capacitance of about 10uf/a (output load) should be closely placed to the input supply pin of the sc4211 to ensure that vin does not sag below 1.4v. also a minimum of 4.7f ceramic capacitor is recommended to be placed directly next to the vin pin. this allows for the device being some dis- tance from any bulk capacitance on the rail. additionally, input droop due to load transients is reduced, improving load transient response. additional capacitance may be added if required by the application. output capacitor: a minimum bulk capacitance of 10f/a (output load), along with a 0.1f ceramic de- coupling capacitor is recommended. increasing the bulk capacitance will improve the overall transient response. the use of multiple lower value ceramic capacitors in parallel to achieve the desired bulk capacitance will not cause stability issues. although designed for use with ce- ramic output capacitors, the sc4211 is extremely toler- ant of output capacitor esr values and thus will also work comfortably with tantalum output capacitors. noise immunity: in very electrically noisy environments, it is recommended that 0.1f ceramic capacitors be placed from in to gnd and out to gnd as close to the device pins as possible. internal voltage selection: by connecting the fb pin to gnd, an internal resistor divider will regulate the output voltage to 1.0v. if the fb pin is connected directly to the vo pin, the output voltage will be regulated to the 0.5v internal reference. external voltage selection resistors: the use of 1% resistors, and designing for a current flow 10a is recommended to ensure a well regulated output (thus r2 50k ? ). applications information
8 ? 2007 semtech corp. www.semtech.com sc4211 power management outline drawing - soic-8-edp see detail detail a a .050 bsc .236 bsc 8 .010 .150 .189 .154 .193 .012 - 8 0.25 1.27 bsc 6.00 bsc 3.90 4.90 - .157 .197 3.80 4.80 .020 0.31 4.00 5.00 0.51 bxn 2x n/2 tips seating aaa c e/2 2x 12 n a d a1 e1 bbb c a-b d ccc c e/2 e a2 (.041) .004 .008 - .028 - - - - 0 .016 .007 .049 .000 .053 8 0 0.20 0.10 - 8 0.40 0.17 1.25 0.00 .041 .010 .069 .065 .005 1.35 (1.05) 0.72 - 1.04 0.25 - - - 1.75 1.65 0.13 0.25 - .010 .020 0.50 - c l (l1) 01 0.25 gage plane h 3. dimensions "e1" and "d" do not include mold flash, protrusions or gate burrs. -b- controlling dimensions are in millimeters (angles in degrees). datums and to be determined at datum plane notes: 1. 2. -a- -h- side view a b c d e h plane exposed pad l1 n 01 bbb aaa ccc a b a2 a1 d e e1 l h e c dim min millimeters nom dimensions inches min max max nom f h h f h .085 .120 .095 .116 .130 .099 2.95 2.15 3.05 2.41 3.30 2.51 4. reference jedec std ms-012, variation ba.
9 ? 2007 semtech corp. www.semtech.com sc4211 power management semtech corporation power management products division 200 flynn road, camarillo, ca 93012 phone: (805)498-2111 fax (805)498-3804 contact information land pattern - soic-8-edp this land pattern is for reference purposes only. consult your manufacturing group to ensure your company's manufacturing guidelines are met. notes: 1. reference ipc-sm-782a, rlp no. 300a. 2. 3. thermal vias in the land pattern of the exposed pad shall be connected to a system ground plane. failure to do so may compromise the thermal and/or functional performance of the device. e z (c) g p ? 0.36mm thermal via x y solder mask (5.20) c (.205) x y z f g p d e .024 .087 .291 .101 .118 .050 .201 .134 0.60 2.20 7.40 2.56 3.00 1.27 5.10 3.40 millimeters inches dim dimensions d f
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