View AD7403_7742836.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

16 - bit , isolated sigma - delta modulator data sheet AD7403 f ea t u r es 5 mh z t o 20 m h z e x t er n al cl o ck in p u t r at e 16 b i t s , n o m is sin g c o d e s s i g na l - to - n o ise r a tio ( s nr ) : 88 d b t y p i c al e ff e c ti v e n u m b e r o f b i ts (e n o b ): 1 4 . 2 b its ty p ic a l t y pi ca l o f fs e t d r ift v s . t e mp e ra t u re : 1 .6 v/ c ty p ic a l on - b o ar d d i g i t al i s o la t o r on - b o a rd re f e re n c e fu l l - s c al e a na l o g i np u t r a ng e : 320 m v ? 40 c t o + 1 2 5 c o pe r a t i n g r a n ge h i g h c om m on - m o d e t r a n sie n t im m u n ity : > 2 5 k v / s 16 - lead , w i de - b od y s o ic , w ith i n c r ea s ed cr e e pa g e pa ck a ge s l e w ra te l i m i te d o u tp u t f o r l ow elec t r o m ag n et i c i n t e r f er en c e ( em i ) s af et y an d r eg u la t o r y ap p r o v als ( p en d i n g ) u l r e c og n i t i on 500 0 v r m s f o r 1 m i n u t e p er u l 1577 c sa c o mp o n e n t a cce pt a n ce n o t i ce 5 a v d e c e r t if ic a te o f c o n f o r m ity d i n v vd e v 0 8 8 4 - 10 ( v d e v 0 884 - 10) : 20 06 - 12 v i o rm = 1 2 50 v pe a k a ppl i c a ti o ns s hu nt c u r r e nt m o ni t o r i n g a c m ot or c on t r ol s p o w er an d s o la r i n v er t er s w in d tu r b in e i n v er t er s d a t a a c q u i si ti o n s y ste ms a n alo g - to - d ig ita l a n d o p to - iso l a to r r e p l a c e m e n ts fu nc ti o na l b l o c k d i a g r am f ig u re 1. g en er a l d es c r i p t i o n t he a d 740 3 1 i s a h i g h p e r f orm a n c e , se co n d - o r d e r , - m o d u l a t or th a t c o n v e r ts a n a n a lo g i n p u t si gn a l i n t o a h i g h sp e e d , si n g le - bi t d a ta s tr e a m , wit h o n - c hi p d ig it a l is o l a t io n ba s e d o n a n a l o g d e v i ce s, i n c. , i c ou p le r ? t e c h n ol o g y . t he a d 7403 op e r a t e s f r om a 5 v (v dd1 ) p o w e r s u p pl y a nd ac c e p t s a di f f e r e n t i al i n p u t si gn a l o f 250 m v ( 320 m v fu ll - s ca l e ) . t he d if f e r e n t ia l i n p u t is i d e a l l y s u i te d to s h u n t v o l ta g e m o n i to r i n g i n h i g h v o l ta g e a p p l i c a t io n s w he r e g a l v a n ic is o l a t io n is r e q u ir e d . t h e a n a l o g i n p u t i s c o n t i n uo us l y s a m p l e d b y a h ig h p e r f o r m a nc e a n a lo g m o d u la t o r , a n d c o n v e r t e d t o a on e s d e ns it y d i gi t a l o ut p u t s t re a m wi th a d a ta r a te of u p t o 20 m h z . t he o r i g in a l in f o r m a t io n c a n b e r e c o n s t r u c t e d wi t h a n a p p r o p r ia t e d ig it a l f i l t e r t o a c h i e v e 8 8 d b s i g n a l t o n o i s e ra t i o (s n r ) a t 7 8 .1 k sps . t he s e r ia l i n p ut / o ut p ut c a n us e a 5 v o r a 3 v s u ppl y ( v dd2 ). t h e s e r i a l i n te r f a c e i s d i g i ta l l y i s o l a te d . h i g h s p e e d c o m p l e m e n t ar y me t al o x i de s e m ic o nd u c t o r ( c mo s ) t e c h n ol o g y , c o m b i ne d w it h m o no l it hi c t ra n sf orm e r t ec h n o l o g y , m ea n s t h e o n - c hi p is o l a t io n p r o vi d es o u t s t a n d i n g p e r f o rm a n c e c h a ra c t e r i s t i c s , s u p e ri o r t o a l te r n a ti v e s su c h a s o p t o c o u p le r d e v i c e s. t he a d 7403 d e vi c e is o f f e re d i n a 1 6 - le a d , wid e - b od y s oi c pa ck a g e a n d h as an o p e r at i n g te m p e ra t u r e ra n g e of ? 4 0 c to + 1 2 5 c . 1 p r o t e c t e d b y u . s . p a t e n t s 5, 952, 849; 6, 873, 065; a n d 7, 075, 329. v dd1 v dd2 AD7403 buf ref clk decoder gnd 1 g nd 2 mda t m cl ki n ( 5m hz t o 20m hz ) 12196- 001 v i n+ v i n? cl k encoder d at a e nco de r cl k de co de r - adc re v. 0 d oc u m e n t f e e d b a c k i n f o r m at i o n f u rn i s h e d b y a n al o g d ev i c e s i s b e l i ev ed t o b e ac c u r at e an d rel i ab l e . h o w ev er , n o res p o n s i b i l i t y i s as s um ed b y a n al o g d ev i c es f o r i t s us e , n o r f o r an y i n f ri n g em en t s o f p at en t s o r o t h e r ri g h t s o f t h i rd p ar t i es t h at m a y res u l t f ro m i t s u s e . s p e c i f i c a ti o n s s u b j e c t to c h a n g e w i th o u t n o ti c e . n o l i c en s e i s g r an t ed b y i m p l i c at i o n o r o t h er w i s e u n d er an y p at en t o r p at en t ri g h t s o f a n al o g d ev i c e s . t r ad em ar k s an d reg i s t ered t r a d em ar k s are t h e p ro p er t y o f t h ei r res p e c t i v e o w n ers . o n e t e c h n ol og y w a y , p .o . b o x 91 0 6, n o rw o o d , m a 02 06 2 - 9 1 06 , u . s . a . t e l : 7 8 1. 32 9. 4 7 00 ? 20 14 a n al o g d ev ic es , i n c . a l l r ig h t s r es er v ed . t e c h n i c a l s u p p or t w w w .a n a l og .c om http://
AD7403 data sheet t abl e of co nt ent s f ea t u r es ................................ ................................ .............................. 1 a ppl i c a t i o n s ................................ ................................ ....................... 1 f u n c t io n a l b l o c k d ia g r a m ................................ .............................. 1 g e ne ra l d e s c ri p t i o n ................................ ................................ ......... 1 r e v is io n h is t o r y ................................ ................................ ............... 2 s pe c i fi c a t i o n s ................................ ................................ ..................... 3 t im in g s p e c if i c a t io n s ................................ ................................ .. 4 p ac k ag e c ha r a c t e r is t ic s ................................ ............................... 5 i n s u l a ti o n a n d s a f e ty re l a te d s p e c i f i c a ti o n s ............................ 5 r e g u l a t o r y i n f o r m a t i o n ( p e nd i ng ) ................................ ............ 5 d in v v d e v 0884 - 10 ( v d e v 0884 - 10) : 2006 - 12 i n sul a t i o n c ha r a c t e r is t ic s ................................ ................................ .............. 6 a bs o l u t e m a x im u m r a t in g s ................................ ............................ 7 e s d c a u ti o n ................................ ................................ .................. 7 p i n c o nf i g u r a t i o n a nd f u nc t i o n de s c r i p t i o n s ............................. 8 t y p i ca l p e r fo r m a n ce c h a r a c t e r i st i cs ................................ ............. 9 t e rmi n o l og y ................................ ................................ .................... 12 t h e or y of op e r a t i on ................................ ................................ ...... 13 c i r c u i t i n f orm a t i o n ................................ ................................ .... 13 a n a l o g in p ut ................................ ................................ ............... 13 d i f f e re n t i a l i n p u t s ................................ ................................ ...... 14 d i gi t a l ou t p u t ................................ ................................ ............. 14 a ppl i c a t i o n s i n f orm a t i o n ................................ .............................. 15 c u r r e n t s e ns i ng a p p l i c a t i o ns ................................ ................... 15 v o lt a g e s e n si n g a p p li c a t i o n s ................................ .................... 15 in p ut f i l t e r ................................ ................................ .................. 16 d ig it a l f il t e r ................................ ................................ ................ 16 i n t e rf a c i n g to a d s p - c m 40x f ................................ .................. 19 g r ou n d i n g a n d l a you t ................................ .............................. 19 i n s u l a t io n l if e t im e ................................ ................................ ..... 19 ou t li n e d i m e n si o n s ................................ ................................ ....... 20 or d e r i n g g u id e ................................ ................................ .......... 20 r e v is io n h i s t o r y 4 /1 4 r e v is io n 0 : i n it ia l ve r s i o n rev. 0 | page 2 of 20
data sheet AD7403 speci fi ca t i ons v dd1 = 4. 5 v t o 5. 5 v , v dd 2 = 3 v t o 5. 5 v , v i n+ = ? 250 m v t o + 250 m v , v in ? = 0 v, t a = ? 40 c t o + 125 c , f m c l ki n 1 = 5 m h z t o 20 m h z , t es t ed w i t h s i n c 3 f i l t er , 2 5 6 d ec i m a t i o n r a t e, a s d ef i n ed b y v er i l o g c o d e, u n l es s o t h er w i s e n o t ed . al l v o l t a g es a r e r el a t i v e t o t h ei r r es p ec t i v e g ro u n d . t a bl e 1 . pa r a m et er mi n ty p ma x un i t t e st c o n d i tio n s/ c o m m e n ts s t a t ic per f o r m an c e re s ol u t i on 16 b i ts f i l te r o u tp u t tr u n c a te d to 1 6 b i t s i n t e g r a l no n l i n e a r i t y ( i nl) 2 2 12 ls b d if f er en t ia l n o n l in ea ri t y ( d n l ) 2 0. 99 ls b g u a ra n t e ed n o m is s ed c o d es t o 16 bi t s o ff s e t er r o r 2 0. 2 0. 7 5 mv o f f s et d r if t v s . t em p e ra t u r e 1. 6 3. 8 v/ c 1.3 3. 1 v/ c 0 c to 85 c o f f s et d r if t v s . v d d1 50 v / v g a in e rr o r 2 0. 2 0. 8 % f sr f mc l k in = 16 m h z 0.2 0. 8 % f s r f mc l k in = 20 m h z , t a = ? 40 c t o + 85 c 0.2 1. 2 % f s r f mc l k in = 20 m h z g a in e rr o r d ri f t v s . t e mp er a t u r e 65 95 ppm / c 40 60 v/ c g a in e rr o r d ri f t v s . v dd 1 0. 6 m v/ v an al o g in pu t inp u t v ol t ag e r an g e ? 320 + 320 mv fu l l -s c al e r an g e ? 250 + 250 mv f o r s p e c if ied p er f o rma n c e i n p u t c o mmo n - m od e v ol t ag e r an g e ? 200 t o + 30 0 mv d y na m i c i np u t c u r r e nt 45 50 a v in + = 250 m v , v in ? = 0 v 0. 0 5 a v in + = 0 v, v in ? = 0 v d c l ea k a g e c u rr e n t 0. 01 0. 6 a i n p u t c a p a ci t a nce 14 pf d y n am ic s pec i f ic a t io n s v in + = 1 k h z si gn a l - to - n oi s e - an d - d i s t or t i on r at i o ( s in ad ) 2 81 87 db 83 87 db ? 40 c t o + 85 c s i g n al - to - no i s e r a t i o ( s nr) 2 86 88 db t ot al h ar m on i c d i s t o r t i on ( t h d ) 2 ? 96 db pe a k harmonic or spurious noise (sfdr) 2 ?97 db e f f ec t iv e n u mb e r o f b it s ( e n o b ) 2 13. 1 14 .2 b i ts 13. 4 14 .2 b i ts ? 40 c t o + 85 c n o is e free code resolution 2 14 b i ts i s o la t i o n t ra ns i e nt i m m u ni t y 2 25 30 k v / s l o g ic in pu t s c m o s w i th s c h m i tt t rig g er i n p u t hi gh v o l t a ge ( v ih ) 0. 8 v d d2 v in p u t l o w v ol t ag e ( v il ) 0. 2 v d d2 v i n p ut curr e n t ( i in ) 0. 6 a i n p u t c a p a ci t a nce ( c in ) 10 pf lo g i c o u tp u ts o utput hi g h v o l ta g e ( v oh ) v d d2 ? 0. 1 v i o = ? 200 a o u tp u t l o w v o l ta g e ( v ol ) 0. 4 v i o = + 200 a r e v. 0 | page 3 of 20
AD7403 data sheet pa r a m et er mi n ty p ma x un i t test conditions/comments po w er r eq u ir em en t s v d d1 4. 5 5. 5 v v d d2 3 5. 5 v i d d1 30 36 m a v d d1 = 5. 5 v i dd2 12 18 ma v dd2 = 5.5 v 6 10 m a v d d2 = 3. 3 v p o w er d is s i p a t io n 23 1 297 mw v d d1 = v dd 2 = 5. 5 v 185 231 mw v d d1 = 5. 5 v , v dd 2 = 3. 3 v 1 f or f m cl k in > 16 m h z , m a r k s p a c e r a t i o i s 48/ 52 t o 52/ 48, v dd1 = 5 v 5% . 2 s ee t h e t e r mi n o l og y s ec t i o n . t im in g s p e c if ic a t io n s v dd1 = 4. 5 v t o 5. 5 v, v dd2 = 3 v t o 5. 5 v , t a = ? 40 c t o + 125 c , u n l es s o t h er w i s e n o t ed . s a m p le t es t ed d u r i n g i n i t i a l r el ea s e t o en su r e c o mp l i an c e . i t i s r e c o mme n de d t o r e ad m d a t o n t h e m c l k i n r i si n g e dg e . t a bl e 2 . pa r a m et er l im i t a t t m in , t m ax un i t d e sc r ip t io n f mc l k in 5 mhz min imum master clock input frequency 20 mh z m ax imu m t 1 1 d at a ac c e s s t i m e af t e r m c l k in ri s in g ed g e 40 n s m ax imu m v d d2 = 4. 5 v t o 5. 5 v 45 n s m ax imu m v d d2 = 3 v t o 3. 6 v t 2 1 d at a h ol d ti m e af t e r m c l k in rising edge 1 2 n s mi n im u m v d d2 = 4. 5 v t o 5. 5 v 1 7 n s mi n im u m v d d2 = 3 v t o 3. 6 v t 3 m as t e r cl oc k l o w t i m e 0. 45 t mclk in n s mi n im u m f mc l k in 16 m h z 0. 4 8 t mc l k in n s mi n im u m 16 m h z < f mc l k in 20 m h z t 4 m a ster c l o c k h ig h t im e 0. 45 t mc l k in n s mi n im u m f mc l k in 16 m h z 0. 48 t mc l k in n s mi n im u m 16 m h z < f mc l k in 20 m h z 1 d ef i n e d a s the ti m e r eq u i r ed f r o m a n 8 0 % m cl k i n i n p u t l ev e l t o w h en t h e o u t p u t c r o s s e s 0 . 8 v or 2 . 0 v f o r v dd2 = 3 v t o 3. 6 v or w h en t h e ou t p u t c r os s es 0 . 8 v or 0 . 7 v dd2 fo r v dd2 = 4. 5 v t o 5. 5 v a s o u t l i n e d i n f i gu r e 2 . m e as u r e d wi t h a 200 a l o ad an d a 25 p f l o ad c ap ac i t an c e . f ig u re 2. da t a t im in g m cl ki n m dat 1 s e e n ote 1 of ta b le 2 for fu r th e r d e ta ils t 4 t 1 t 2 t 3 80% 2.0v or 0.7 v dd2 1 0. 8v 12196-002 r e v. 0 | p a ge 4 o f 20
data sheet AD7403 p ac k ag e c har a c t e r i s t ic s t a bl e 3 . parameter symbol min typ max unit test conditions/comments resistance (input to output) 1 r i - o 10 12 c a p a c i ta n c e ( i n p u t to o u tp u t) 1 c i - o 2. 2 pf f = 1 m h z i c j u nc t i o n t o a m b i e nt t her m a l r es i s t a nc e ja 45 c / w t h ermo c o u p l e l o c a t ed a t c e n t er o f p a c k a g e u n d ers id e , t e s t c o n duc t e d o n 4 -l a y er b o a r d w it h t h in t ra c es 1 t h e d ev i c e i s c on s i d e r e d a 2 - t e r mi n a l dev i c e: p i n 1 t o p i n 8 a r e s h o r t e d t o g et h e r , a n d p i n 9 t o p i n 1 6 a r e s h o r t e d t og et h e r . i ns u l a ti o n a nd s a fe t y r e lat e d s p e c i f i c at i o ns t a bl e 4 . pa r a m et er sy m b o l v alu e un i t t e st c on d i t i on s / c o m m e nt s i n p u t to o u tp u t m o m e n ta r y w i th s ta n d v ol t ag e v is o 500 0 m i n v 1 min ute duration m in i mu m e x t er n a l a ir g a p ( c l ea r a n c e) l ( i 0 1) 8 .3 min 1 , 2 mm m ea sured from input terminals to output terminals, shortest distance through air m in i mu m e x t er n a l t ra c k i n g ( c r e ep a g e) l ( i 0 2) 8 . 3 min 1 mm m ea sured from input terminals to output terminals, shortest distance path along body m in i mu m i n t ern a l g a p ( i n t ern a l c l ea ra n c e) 0. 0 34 min mm d i s t a nc e t h r ou g h i n s u l at i on t ra c k i n g r es i s t a n c e ( c o mp a ra t iv e t ra c k in g i n d ex ) c ti > 400 v d i n iec 112/vde 0303 part 1 3 i s ol at i on g r ou p ii m a t e r i a l gr o u p ( d i n v d e 0110, 1 / 89, t a b l e i ) 3 1 i n ac c o r d an c e wi t h i e c 60950 - 1 g u i d el i n es f o r t h e mea s u r e m en t of c r ee p a g e a n d c l ea r a n c e di s t a n c e s f or a p ol l u t i o n d eg r e e of 2 a n d a l t i t u d e s 2000 m . 2 co n s i d er a t i o n m u s t b e g i v en t o p a d l a y o u t t o e n s u r e t h e m i n i m u m r eq u i r ed di s t a n c e f or c l ea r a n c e i s ma i n t a i n e d. 3 cs a ct i r a t i n g f o r t h e a d 7403 i s > 6 00 v an d a m at e r i al g r o u p i is o l a t io n g r o u p . r e g u lat o r y i n f o r m a t i o n ( pe nd i ng ) a ppr o v a l s f o r t he a d 7403 b y t h e o r ga n i z a t i o n s li st e d i n ta b l e 5 a r e p en d i n g . t a bl e 5 . ul ( p e nd i ng ) 1 cs a (p e n d in g ) v de ( p e nd i ng ) 2 r ec o g n iz ed u n d e r 1577 c om p on e n t r e c og n i t i on pr o gr a m 1 a p p r o v e d un de r c s a c o mp o n en t a ccep t a n ce n o t ice 5a c er t if ied a cco r d in g t o d i n v v d e v 0 8 8 4 - 10 ( vd e v 0 8 8 4 - 1 0) : 2 006 - 12 2 500 0 v rms i s ol at i o n v ol t ag e s in g l e p r o t e c t io n b as i c i ns u l a t i o n p er c s a 60 95 0 -1 -07 a n d i e c 60 950 - 1, 830 v r m s ( 117 3 v pe a k ) ma x imu m w o rk in g v o l t a g e 3 r ein f o r ce d i n s u l at i on p e r d i n v v d e v 0 8 8 4 - 10 ( vd e v 0 8 8 4 - 10) : 2 006 - 12 , 12 50 v pe a k r ein f o r c ed i n s u l a t io n p er c s a 60 950 -1 - 07 a n d iec 60 95 0 - 1, 415 v r m s ( 58 6 v pe a k ) ma x imu m w o rk in g voltage 3 r ein f o r c ed in s u l a t io n p er i e c 6 0 6 0 1 - 1, 25 0 v r m s ( 35 3 v pe a k ) ma x i mu m w o rk in g v o l t a g e f il e e 2141 00 file 2050 78 f il e 24 71900 - 48 80 - 0 001 1 i n ac c o r d an c e wi t h u l 1577, e a c h a d 7 403 i s p r oo f t e s t e d by a p p l y i n g a n i n s u l a t i o n t e st v o l t a g e 6 0 0 0 v r m s f o r 1 s e c on d ( c u r r en t l ea ka g e d et ec t i o n l i mi t = 1 5 a) . 2 i n a c c o r d a nc e w i t h di n v v de v 0 8 8 4 - 10, e a c h a d 7403 i s pr o o f te s te d by a ppl y i ng a n i nsu l a t i o n t e st v o l t a g e 23 44 v p e ak f or 1 s ec o nd ( p ar t i al d i s c h a rg e d et ec t i on l i mi t = 5 p c) . 3 ra ti n g i s c a lc u l a t e d f o r a p o l l u t i o n d eg r e e o f 2 a n d a m a t e r i a l g r o u p i i i . t h e a d 7403 ri - 16 - 2 p a c ka g e ma t er i a l i s r a t e d b y cs a t o a ct i o f >6 0 0 v a n d t h er ef o r e m at e r i al g r o u p i. r e v. 0 | page 5 o f 20
AD7403 data sheet d i n v vd e v 0 8 8 4 - 10 ( v d e v 0884 - 10) : 2 006 - 1 2 i n s u l at i o n c har ac t e r i s t i c s t his is o l a t o r is s u it a b l e f o r r e in f o r c e d e l e c t r i c a l is o l a t io n o n l y w it hin t he s a f e t y l im i t d a t a . m a in t e n a n c e o f t he s a f e t y d a t a i s e n su r e d b y m e a ns o f p r o t e c t iv e c i r c u it s . t a bl e 6 . d e sc r ip t io n sy m b o l ch ar ac t er i s t i c unit in s t al l a t io n c l as s if ic a t io n per din v de 0 1 1 0 f or r a t e d mai n s v ol t ag e 300 v r m s i t o iv f or r a t e d mai n s v ol t ag e 450 v r m s i t o iv f or r a t e d mai n s v ol t ag e 600 v r m s i t o iv f or r a t e d mai n s v ol t ag e 1000 v r m s i t o iv c l im a t ic c l as s if ic a t io n 40/ 1 05/ 2 1 po l l u t io n deg r ee ( din v de 0 1 1 0 , t ab l e 1 ) 2 m a x i m u m w o rk i ng i ns u la t i o n v o l t a g e v iorm 12 50 v peak in pu t to output test voltage, method b1 v iorm 1. 875 = v pr , 1 0 0 % p ro d u c t i o n t e s t , t m = 1 s ec on d , p a r t ia l d is c h a r g e < 5 pc v p d (m ) 2 34 4 v pe a k in pu t t o o u tp u t te s t v o l t a g e , me th o d a v pr (m ) a fte r e n v iro n me n t a l t e s t s u b g ro u p 1 v iorm 1. 6 = v pr , t m = 6 0 s e co nd s , p a r t i a l d i s cha r g e < 5 p c 200 0 v pe a k a f t er input and/or safety test subgroup 2/ safety test subgroup 3 v iorm 1. 2 = v pr , t m = 6 0 s e co nd s , p a r t i a l d i s cha r g e < 5 p c 150 0 v pe a k hig hes t allowable overvoltage (transient overvoltage, t tr = 10 seconds) v iotm 8000 v peak s u rg e i s o la t i o n v o l t a g e v i osm v pe a k 1. 2 s r i s e t i m e , 50 s , 5 0 % f a l l t ime 120 00 v pe a k s af e ty limiting values (maximum value allowed in the event of a failure, see figure 3 ) case t e mp e ra t u r e t s 150 c s i de 1 (p v d d1 ) a n d s i de 2 (p v d d2 ) p o w er d is s i p a t io n p so 2. 78 w in s u l a t io n r es is t an c e a t t s , v io = 500 v r io > 10 9 f igure 3 . t h erm a l dera t in g c u rv e, dep en d en ce o f s a f et y l im it in g v a lu es w it h c a s e t em p era t u re p er di n v v de v 0 8 8 4 - 10 0 1 2 3 4 0 50 100 150 200 sa f e o per a tin g p owe r ( w) a mb i en t t emper a t ure ( c) 12196-003 r ev. 0 | p a ge 6 o f 20
data sheet AD7403 absol ut e m axi m u m ra t i ngs t a = 2 5 c , u n le ss o t h e r w i s e n o t e d . a ll v o l t a g e s a r e r e la t i v e t o t h ei r r es p ec t i v e g r o u n d . t a bl e 7 . pa r a m et er r a tin g v dd1 to gnd 1 ?0.3 v to +6.5 v v dd2 to gnd 2 ?0.3 v to +6.5 v analog input voltage to gnd 1 ? 1 v to v dd1 + 0.3 v digital input voltage to gnd 2 ?0.3 v to v dd 2 + 0.5 v output voltage to gnd 2 ?0.3 v to v dd2 + 0.3 v input current to any pin except supplies 1 10 ma operating temperature range ?40c to +125c storage temperature range ?65c to +150c junction temperature 150c pb - free temperature, soldering r e f l ow 260 c e sd 2 kv 1 t r a n s i e n t c u r r en t s o f u p t o 1 0 0 ma d o n ot c a u s e s cr t o l a t c h u p . s t r es s es a t o r a b o v e t h o s e l i s t ed u n d er a b s o l u t e m a x i m u m r a t i n gs m a y c a u s e p er m a n en t d a m a g e t o t h e p r o d u c t . t h i s i s a s tr e s s r a ti n g o n l y ; f u n c ti o n a l o p e r a ti o n o f th e p r o d u c t a t th e s e o r a n y ot h e r c o n d i t i o n s a b o v e t h os e i n d i c a t e d i n t h e op e ra t i o n a l s e c t i on of t h i s s p e c i f i c a t i on i s n ot i m p l i e d . o p e r a t i on b e yon d t h e max i m u m o p e ra t i n g c o n d i t i o n s f or e xt e n d e d p e ri o d s m a y a f f e c t p ro d u c t re l i a b i l i t y . t a bl e 8 . m ax i m um c o n t i n uo u s w o r k i n g v o l t age 1 pa r a m et er ma x un i t co n s t r ai n t ac v o l t a ge b ip o l a r w a v ef o rm 125 0 v peak 20 - year minimum l if et im e ( v de a p p r o v ed w o rk in g voltage) u n i p ol ar w av e f or m 125 0 v pe a k 20 - y ea r mi n imu m lifetime dc voltage 125 0 v peak 20 - year minimum lifetime 1 r ef e r s t o c o n t i n u o u s v o l t a g e ma g n i t u de i m p o s e d a c r os s t h e i s ol a t i o n b a r r i er . e s d c au t i o n r e v. 0 | p a ge 7 o f 20
AD7403 data sheet pi n confi gur a t i on an d funct i on de scri pt i ons f ig u re 4. p in c o n f ig u ra t io n t a bl e 9 . pin f u n ct io n d e s cr ip t io n s p i n n o. m ne m o ni c d e sc r ip t io n 1 , 7 v dd1 supply voltage, 4.5 v to 5.5 v. this is the supply voltage for the isolated side of the AD7403 and is relative to gnd 1 . for device operation, connect the supply voltage to both pin 1 and pin 7. decouple each supply pin to gnd 1 with a 10 f capacitor in parallel with a 1 nf capacitor. 2 v in+ positive analog input. 3 v in ? n eg a t iv e a n a l o g i n p u t . n o rma l l y c o n n ec t ed t o g n d 1 . 4, 8 gnd 1 ground 1. this pin is the ground reference point for all circuitry on the isolated side. 5, 6 n i c no t i nt e r na l l y c o nn e ct e d . t he s e pi n s a r e no t i nt e r na l l y co nne c t e d . c o nne c t t o v d d1 , gn d 1 , o r l ea v e f l o a t in g . 9, 16 gn d 2 g r o u n d 2 . t h is p in is t h e g r o u n d r ef er en c e p o i n t f o r a l l c ir c u it r y o n t h e n o n is o l a t ed s id e . 10, 12, 15 nic not internally connected. these pins are not internally connected. connect to v dd2 , gnd 2 , or leave floating. 11 m dat serial data output. the single bit modulator output is supplied to this pin as a serial data stream. the bits are clocked out on the rising edge of the mclkin input and are valid on the following mclkin rising edge. 13 mclkin master clock logic input. 5 mhz to 20 mhz frequency range. the bit stream from the modulator is propagated on the rising edge of the mclkin. 14 v dd2 supply voltage, 3 v to 5.5 v. this is the supply voltage for the nonisolated side and is relative to gnd 2 . decouple this supply to gnd 2 with a 100 nf capacitor. v dd1 1 v in+ 2 v in? 3 g nd 1 4 g nd 2 16 ni c 2 15 v dd2 14 mclkin 13 ni c 1 5 ni c 2 12 ni c 1 6 md a t 1 1 v dd1 7 ni c 2 10 g nd 1 8 g nd 2 9 1 ni c = no t i nt e rnal l y co nne ct e d. co nne ct t o v dd1 , gn d 1 , or le a ve f l o a tin g. 2 ni c = no t i nt e rnal l y co nne ct e d. co nne ct t o v dd2 , gn d 2 , or le a ve f l o a tin g. a d 7403 t op vi ew ( no t t o s cal e) 12196-004 rev. 0 | p a ge 8 o f 20
data sheet AD7403 t ypi cal perfor m a nce cha ract eri st i cs t a = 25 c , v dd1 = 5 v, v dd2 = 5 v, v in + = ? 250 m v t o + 250 m v , v i n? = 0 v, f mc l k i n = 20 m h z , u si n g a s in c 3 f il t e r wit h a 2 5 6 o v e r sa m p li n g ra t i o ( o sr ) , u n le ss o t h e r w i s e n o t e d . fig u re 5 . p sr r v s . su ppl y r i ppl e f r e qu e n c y fig u re 6. c m r r v s . c o mmo n - m o d e r ip p le f req u en cy figu re 7 . s i na d v s . a n a lo g i n p u t f req u en cy f ig u re 8 . t y p ica l f a s t f o u rier t ra n s f o rm ( f f t ) figu re 9 . t y p ica l dnl e rro r figu re 1 0 . t y p ica l i nl e rro r ?120 ?100 ?80 ?60 ?40 ?20 0 0 200 400 600 800 1000 p s rr ( d b) su pp l y r i ppl e f r eq u en c y ( khz ) 200 m v p -p s i n e w av e on v dd 1 1n f d e c o u p l i n g 12196-005 m c l k i n = 20 m h z mc l k i n = 10 m h z ?140 ?120 ?100 ?80 ?60 ?40 ?20 0 0. 1 1 10 100 1000 cm rr ( d b) r i ppl e f r eq u en c y ( khz ) s ho r t e d i n p u t s 200 m v p -p s i n e w av e on i n p u t s m cl kin = 2 0 mh z , s i n c 3 decim a tion r a te = 2 5 6 m cl ki n = 1 0 mh z , s i n c 3 decim a tion r a te = 2 5 6 m cl ki n = 2 0 mh z , u n f il t e r e d 12196- 006 m cl ki n = 1 0 mh z , u n f il t e re d 70 72 74 76 78 80 82 84 86 88 90 100 1k 10k s i nad ( d b) anal o g i np ut f re q ue ncy ( hz ) 16mhz mclkin, v dd1 = 4. 5v 16m hz m cl ki n, v dd1 = 5.0v 16m hz m cl ki n, v dd1 = 5.5v 20m hz m cl ki n, v dd1 = 4.5v 20m hz m cl ki n, v dd1 = 5.0v 20m hz m cl ki n, v dd1 = 5.5v 12196-007 ?160 ?140 ?120 ?100 ?80 ?60 ?40 ?20 0 0 5 10 15 20 25 30 m ag ni t ude ( d b) f re q ue nc y ( khz ) s n r = 88 . 6d b f in = 1khz s i n a d = 88 . 3db t hd = ?100 . 5db 12196- 008 0 10 20 30 40 50 60 dn l e rro r ( l s b) co de ( k) 12196-009 ?1.0 ?0.8 ?0. 6 ?0. 4 ?0. 2 0 0. 2 0. 4 0. 6 0. 8 1. 0 0 10 20 30 40 50 60 in l e rro r ( l s b) co de ( k) 12196-010 ?1.0 ?0.8 ?0. 6 ?0. 4 ?0. 2 0 0. 2 0. 4 0. 6 0. 8 1. 0 r e v. 0 | p a ge 9 o f 20
AD7403 data sheet f ig u re 1 1 . hi stog r am of c od e s at c od e c e n te r f ig u re 1 2 . s nr a n d s i na d v s . t em p era t u re f ig u re 1 3 . t h d a n d s f dr v s . t em p era t u re f ig u re 1 4 . o f f s et v s . t em p era t u re f ig u re 1 5 . g a in e rro r v s . t em p era t u re f ig u re 1 6 . i dd1 vs . v dd1 a t v a rio u s t em p era t u res an d c l oc k r ate s 0 1147 144470 692381 160941 1061 0 0 100 200 300 400 500 600 700 800 32764 32765 32766 32767 32768 32769 32770 hi t s p e r co de ( k) co de m clki n = 10m hz v i n+ = v i n? = 0v 1 m sa mpl es 12196- 011 60 70 80 100 90 ?50 ?25 0 25 50 75 100 125 150 s nr and s i nad ( d b) t emper a t ure ( c) s n r s i n ad 12196- 012 f in = 1khz ?120 ? 1 10 ?100 ?90 ?80 ?70 ?60 ?50 ?25 0 25 50 75 100 125 150 t hd and s f dr ( d b) t emper a t ure ( c) t h d s f dr 12196- 013 f in = 1khz ?200 ?150 ?100 ?50 0 50 100 150 200 ?50 ?25 0 25 50 75 100 125 150 o f f set ( v) t emper a t ure ( c) m c l k i n = 20 m h z 12196-014 ?10 ?8 ?6 ?4 ?2 0 2 4 6 8 10 ?50 ?25 0 25 50 75 100 125 150 g ai n e rro r ( mv ) t emper a t ure ( c) m c l k i n = 10 m h z mc l k i n = 20 m h z 12196- 015 0 5 10 15 20 25 30 35 4. 50 4. 75 5. 00 5. 25 5. 50 i dd1 ( ma) v dd1 (v) mc l k i n = 20 m h z , ?40 c mc l k i n = 20 m h z , +2 5 c mc l k i n = 20 m h z , +8 5 c mc l k i n = 20 m h z , +1 2 5 c mc l k i n = 10 m h z , ?40 c mc l k i n = 10 m h z , +2 5 c mc l k i n = 10 m h z , +8 5 c mc l k i n = 10 m h z , +1 2 5 c 12196-016 r e v. 0 | p a ge 10 o f 20
data sheet AD7403 f ig u re 1 7 . i dd1 vs . v in + dc i n p u t a t v a rio u s t em p era t u res f ig u re 1 8 . i dd2 vs . v dd2 a t v a rio u s t em p era t u res an d c l oc k r ate s f ig u re 1 9 . i dd2 vs . v in + dc i n p u t a t v a rio u s t em p era t u res f ig u re 2 0 . i in + vs . v in + d c i n pu t at v ar i o u s c l oc k r ate s 25 26 27 28 29 30 31 32 ?250 ?125 0 125 250 i dd1 ( ma) v i n+ dc i np ut ( mv ) d c i n p u t t a = ?40 c t a = 0 c t a = +2 5 c t a = +8 5 c t a = +1 2 5 c 12196-017 0 2 4 6 8 10 12 14 3. 0 4. 0 3. 5 4. 5 5. 0 5. 5 i dd2 ( ma) v dd2 (v) mc l k i n = 20 m h z , ?40 c mc l k i n = 20 m h z , +2 5 c mc l k i n = 20 m h z , +8 5 c mc l k i n = 20 m h z , +1 2 5 c mc l k i n = 10 m h z , ?40 c mc l k i n = 10 m h z , +2 5 c mc l k i n = 10 m h z , +8 5 c mc l k i n = 10 m h z , +1 2 5 c 12196-018 10 1 1 12 13 14 ?250 ?125 0 v i n+ dc i np ut ( mv ) 125 250 i dd2 ( ma) d c i n p u t 12196-019 t a = ?40 c t a = 0 c t a = +2 5 c t a = +8 5 c t a = +1 2 5 c ?60 ?40 ?20 0 20 40 60 ?320 ?240 ?160 ?80 0 80 160 240 320 i i n+ ( a) v i n+ dc i np ut ( mv ) mclkin = 5 m h z mclkin = 1 0 mh z mclkin = 2 0 m h z d c i n p u t 12196-020 rev. 0 | p a ge 11 o f 20
AD7403 data sheet t erm i nol ogy d if f e r e n t ia l n o n l in e a r it y ( d n l ) d n l i s t h e d i f f er en c e b et w een t h e m ea s u r ed a n d t h e i d ea l 1 l s b c h a n g e b et w een a n y t w o a d j a c en t c o d es i n t h e ad c . i n t e g r al n o n l i n e ar i t y (in l ) i nl i s t h e max i m u m de v i a t i o n f r o m a s t r a i g h t l i n e p a s s i n g t h ro u g h t h e e n d p oi n t s of t h e a d c t ra n s f e r f u n c t i on . t he e n d p o i n ts o f th e tr a n s f e r f u n c t i o n a r e s p ec i f i ed n eg a t i v e f u l l s c a l e , ? 250 m v ( v in + ? v in ? ) , c o d e 716 8 f o r t h e 1 6 - b it l e v e l, a n d sp e c i f i e d p o si t i v e f u ll s c a l e , + 250 m v ( v in + ? v in ? ), c o d e 58 ,36 8 f o r th e 1 6 - b i t le v e l. o ffs e t e r r o r o f f s et er r o r i s t h e d e vi a t i o n o f t h e m i d s c a l e c o d e ( 3 2 ,768 f o r t h e 16 - b i t le v e l) f r o m t h e i d e a l v in + ? v in ? (t h a t i s , 0 v ). g a i n err o r t he g a in e r r o r in c l u d e s b o t h p o s i t i v e f u l l - s c a l e g a i n e rro r a n d n eg a t i v e f ul l - s c a l e g a i n e rror . p os i t i v e f u l l - s c a l e g a i n e r ror i s t h e d e v i a t i o n o f t h e s p ec i f i ed p o si t i ve f u l l - s ca l e co d e ( 5 8 ,36 8 f or t h e 16 - b i t le v e l) f r o m t h e i d e a l v in + ? v in ? (2 5 0 m v ) a f t e r t h e o f f s e t e r r o r i s a d j u st e d o u t . n e ga t i v e f u ll - s c a l e g a i n e rro r i s t h e d e v ia t io n o f the s p e c if ie d n e g a t iv e f u l l - s ca l e co d e ( 7 1 6 8 f or t h e 16 - b i t le v e l) f r o m t h e i d e a l v in + ? v in ? (? 2 5 0 m v ) a f t e r t h e of f s e t e r r or i s a d j u st e d ou t . si g n a l -to -noi s e -an d -d is t o r t io n r a t io ( s i n a d ) s i na d is the m e a s u r e d ra t io o f s ig n a l to n oi s e an d d i sto r ti o n a t t he o u t p u t o f the a d c . t he s ig n a l is the rm s va l u e o f t h e s i n e w a v e , a n d n o i se i s t h e r m s su m o f a ll n o n f u n d a m e n t a l si gn a ls u p t o h a lf t h e sa m p li n g f r e q u e n c y ( f s /2 ) , in c l u d in g ha r m o n i c s , b ut e x c l u d i n g d c . si g n a l -to -n o i s e r a t i o ( s nr ) s n r i s th e m e a su r e d r a ti o o f s i g n a l to n o i s e a t th e o u tp u t o f th e a d c . t he s i g na l is t he r m s a m p l i t u d e o f t he f u nd a m e n t a l . n o is e i s t h e su m o f a ll n o n f u n d a m e n t a l si gn a ls u p t o h a lf t h e sa m p li n g f re qu e n c y ( f s / 2 ) , e x cl u d i n g d c. t he r a t i o is d e p e nd e n t o n t he n u m b e r o f q u a n t i za t i o n l e v e l s i n t he d ig it i za t i o n p r o c e s s : t he g re a t e r t h e n u m b e r o f l e v e l s , t h e s m a l l e r th e q u a n ti z a ti o n n o is e . t he the o r e t ic a l s ig n a l - to - n o i s e ra t i o f or a n i de al n - b i t c o n v e r te r wi t h a s i n e w a v e i n p u t i s g i v e n b y si g na l - to - n oi s e r a t i o = ( 6. 02 n + 1. 76 ) db t h e re f o re , f o r a 1 2 - b i t c o n v e r te r , th e s n r i s 7 4 d b. i s o l a ti o n t r a n s i e n t i m m u n i ty t he is o l a t io n t r a n s ie n t im m u n i t y s p e c if ie s the r a t e o f r is e a n d f a ll o f a t r a n si e n t p u ls e a p p li e d a c r o ss t h e i s o la t i o n b o u n d a r y , b e y o n d w hic h c l o c k o r d a t a is c o r r u p t e d . t he a d 7403 wa s t e s t e d us i n g a t r a n si e n t p ul s e f r e q ue n c y o f 100 k h z . t ot a l h a r m on i c d i s t or t i on ( t h d ) t h d is the ra t i o o f t he r m s s u m o f ha r m o n ic s to the f u n da me n t al . f o r t h e a d 7403 , it is d e f in e d a s 1 6 5 4 3 2 v v v v v v thd 2 2 2 2 2 log 20 (db) + + + + = w h er e: v 1 i s t h e r ms amp l i t u d e o f t h e f u n d am e n t a l . v 2 , v 3 , v 4 , v 5 , an d v 6 a r e t h e r m s a m p l i t u d es o f t h e s ec o n d t hr o u g h t he s ix t h ha r m o n i c s . p e a k h a r m on i c or s p u r i ou s noi s e ( s f dr ) p e a k ha r m o n ic o r s p u r i o u s n o is e is d e f in e d a s the ra t io o f t he r m s va l u e o f t h e n ex t l a r g es t c o m p o n en t i n t h e ad c o u t p u t s p e c t r u m (u p to f s / 2 , ex c l u d i n g d c ) t o t h e r m s va l u e o f t h e f u n d a m e n t a l. n o r m a lly , t h e v a lu e o f t h i s sp e c i f i c a t i o n i s d et er m i n ed b y t h e l a r g es t h a r m o n i c i n t h e s p ec t r u m , b u t f o r a d c s w he r e the ha r m o n ic s a r e b u r ie d i n the n o is e f l o o r , it is a n o is e p e a k. e f f e ct iv e n u m b e r o f b it s ( e n o b) e n o b i s d e f i ne d b y en o b = ( s in ad ? 1. 76 ) / 6. 02 b i t s n o i s e f r e e c o d e r es o l u t i o n n o i s e f r ee c o d e r e s o l ut i o n r epr es en t s t h e r e s ol u t i on in b it s f or w hic h t he r e is n o c o d e f l ic k e r . t he n o i s e f r ee c o d e r e s ol u t i on f or a n n - b i t c on v e r t e r is d e f i ne d as n o ise fr ee c o d e reso l u t io n ( b it s ) = l og 2 (2 n / p e a k - t o - p ea k n oi s e ) t h e p ea k - t o - p e a k n o i s e i n l sbs i s m e a s u r e d w ith v i n+ = v i n? = 0 v. c om m on -m o d e re j e c t i o n r a t i o ( c m rr) c m rr i s d e f i n e d a s th e r a ti o o f th e p o w e r i n th e a d c o u t p u t a t 250 m v f re qu e n c y , f , to t h e p ow e r o f a + 250 m v p e a k - to - p e ak si n e w a v e a p p l i ed t o t h e c o m m o n - mo de v o l t ag e o f v i n+ an d v in ? o f f re qu e n c y , f s , a s c m rr (d b ) = 1 0 lo g( p f/ p f s ) w h er e: p f i s th e p o w e r a t f r e q u e n c y , f , i n th e a d c o u tp u t. pf s i s th e p o w er a t f r eq u en c y , f s , in t he a d c o u t p u t . p o w e r s u p p l y r e j e ct io n r a t io ( ps r r ) v a r i a t i o n s i n p o w e r su p p ly a f f e c t t h e f u ll - s c a le t r a n si ti o n b u t n o t th e l in e a r it y o f t h e c o n v er t er . p s r r is the m a x im u m c ha n g e in the s p e c i f ie d f u l l - s c a l e ( 2 5 0 m v ) t ra n s i t i o n p o i n t d u e to a c h a n g e i n p o w er s u p p l y vo lt a g e f r o m t h e n o m i n a l va l u e. rev. 0 | page 12 of 20
data sheet AD7403 t heor y of opera t i on c ir c u it in f o r m a t io n t he a d 7403 i s o l at e d - m o d u la t o r c o n v e r t s a n a n a lo g i n p u t s ig n a l i n t o a hig h sp e e d ( 2 0 m h z m a x i m u m ) , si n g le - b i t d a ta s t r ea m ; t h e t i m e a v er a g e si n g le - b i t d a ta f r o m th e m o d u l a to r i s d ir e c t l y p r o p o r t io n a l t o t he i n p u t s ig n a l . f i g u re 21 sh o w s a t y pi c a l a ppl i c a t i o n c i r c u i t w h e r e t h e a d 7403 i s u s ed t o p r o vi d e i s o la t i o n b e t w e e n t h e a n a l o g i n p u t , a c u r r e n t s e n si n g r e si st o r or s hu n t , a n d t he d ig it a l o u t p u t , w hic h is t he n p r o c e s s e d b y a d ig i t a l f il t er t o p r o vi d e a n n - bi t wo r d . a na l o g i npu t t he d if f e r e n t ia l a n a l o g in p u t o f t he a d 7403 i s i m p l em en t ed w it h a s w it c h e d c a p a c it o r c i r c u it . t his c ir c u i t im p l e m e n t s a s e c on d - o r de r mo d u la t o r s t ag e t h a t di g it ize s the i n p u t s ig n a l i n t o a si n g le - b i t o u t p u t s t r e a m . t h e sa m p le c lo c k ( m c l k i n ) p r o v i d e s t h e c lo c k si gn a l f o r t h e c o n v e r si o n p r o c e ss a s w e ll a s th e o u tp u t d a ta f r a m i n g c lo c k . t h i s c lo c k s o u rc e i s e xt e rn a l o n t he a d 7403 . t h e a n a lo g i n p u t s i gn a l i s c o n t i n u o u sl y sa m p le d b y th e m o d u la to r a n d c o m p a r e d to a n i n te r n a l v o l ta g e re f e r en c e. a d i g i t a l s t r ea m t h a t a c c u r a t el y r epr es en t s th e an a l o g i n p u t o v e r ti m e a p p e a r s a t th e o u t p u t o f th e c o n v e r te r ( s ee f i g u re 22 ). a d if f e r e n t i a l si gn a l o f 0 v i d e a l l y r e su l t s i n a s t r e a m o f al t e r - n a t i n g 1 s a n d 0 s a t t he m d a t o u t p u t p in . t his o u t p u t is hig h 5 0 % o f t h e t i me a n d l o w 5 0 % o f t h e t i me . a d i f f e r e nt i a l i np u t of 2 50 m v p r o du c e s a s t r e am o f 1 s an d 0 s t h a t ar e h i g h 8 9. 06 % o f t he t im e . a d i f f e re n t i a l i n p u t o f ? 2 5 0 m v p ro d u c e s a s t re a m of 1s a n d 0s t h a t a r e h i g h 10. 94 % o f the tim e . a d i f f e r e n t i a l i n p u t o f 320 m v i de al l y r e su l t s i n a st r e a m o f a ll 1 s. a d i f f er en t i a l i n pu t o f ? 3 2 0 mv i de al l y r e su l t s i n a s t r e a m o f a ll 0 s. t h e a b s o l ut e f u l l - s c a le r a n g e i s 3 20 m v an d th e s p e c i f i e d fu l l - s c a l e p e rf orm a n c e ra n g e i s 25 0 mv , a s sh o w n i n ta b le 10 . t a bl e 10 . a n al o g in p ut r an ge a na l o g i np u t v o l t a ge i n pu t (m v ) p o s it iv e f u l l - s c al e va l u e + 320 p o s it iv e s p e c if ied p er f o r ma n c e i n p ut + 250 zero 0 n eg a t iv e s p ec if i ed p er f o r ma n c e i n p ut ? 250 n eg a t iv e f u l l - s c al e va l u e ? 320 f ig u re 2 1 . t y p ica l a p p lica t io n circuit f ig u re 2 2 . a n al og i n p u t v s. m od u l ator o u tp u t - mod/ encoder nonis ol a t ed 5v / 3v v dd1 g nd 1 v i n+ v i n? g nd 1 v dd1 v dd g nd v dd2 md a t md a t s i nc3 f i l t e r* a d 7403 m clki n sda t cs s cl k m cl k 100n f g nd 2 de co de r 1nf 10 f + 400v ?400v 220p f 220p f 10? 5. 1v r s hunt 10? decode r e nco de r 12196- 022 1n f 10 f g a t ed dri v e ci rcui t flo a tin g po w er su pp l y ga t ed dri v e ci rcui t flo a tin g po w er su pp l y mot or *this fi l ter is impl emen t ed with an f p g a o r ds p modul a t o r o ut p ut +f s anal o g i np ut ?f s anal o g i np ut anal o g i np ut 12196-021 r e v. 0 | p a ge 13 of 20
AD7403 data sheet t o r e c o n s tr u c t th e o r i g i n a l i n f o r m a ti o n , th i s o u tp u t m u s t b e di g i t al l y f i l t e r e d a n d de c i ma t e d. a s i n c 3 f i l t e r i s r e c o mme n de d b ec a u s e i t i s on e o r d e r hig he r t ha n t h a t o f t he a d 74 03 m o d ul a t o r , w hic h is a s e c o n d - o r de r mo d u l a t o r . i f a 2 5 6 de c i ma t i o n r a t e i s u s e d , t h e r e su l t i n g 1 6 - bi t wo r d r a t e i s 7 8 .1 k sp s , a ssu m i n g a 20 m h z ex t er n a l c l o c k f r eq u en c y . s ee t h e d ig it a l f il t e r s e c t i on f o r m o re d e t a i l e d i n f orm a t i on on t h e s i n c f i l t e r i m p l e m e n t a t i on . f i g u re 23 s h o ws th e tr a n s f e r f u n c ti o n o f th e a d 7403 re l at i v e t o t he 1 6 - b i t o u tp u t. f ig u re 2 3 . f ilt er ed a n d decim a t ed 1 6 - b it t ra n sf er f u n ct io n d i ffe r e nti a l i npu ts t h e a n a l o g i n p u t to th e m o d u l a t o r i s a s w i tc h e d c a p a c i to r d e si gn . t h e a n a lo g si gn a l i s c o n v e r t e d i n t o c h a r g e b y h i g h l y li n e a r sa m p li n g c a p a c i t o r s. a si m p l i f i e d e q u i v a le n t c i r c u i t d ia g r a m o f t he a n a l o g i n p u t is s ho w n in f i g u re 24 . a si gn a l s o u r c e d r i vi n g t h e a n a l o g i n p u t m u st p r o vi d e t he c h a r g e o n t o t h e s a m p l i n g c a p a c i t o r s e v e r y h a l f m c l k i n c y c l e a n d s e t t l e t o t h e r e q u i r e d a c c u r a c y w it hi n t he ne x t ha l f c y c l e . f ig u re 2 4 . a n a lo g i n p u t e q u iv a len t c ir cu it b ec a u s e t h e a d 7403 sa m p le s t h e d i f f e r e n t i a l v o lt a g e a c r o ss i t s a na l o g i n p u t s , l o w no i s e p e r f o r m a nc e i s a t t a i ne d w i t h a n i n p u t c ir c u it tha t p r o v id e s l o w c om m on - m o d e n o is e a t e a c h in p u t . d i g i t al o ut p ut t he a d 7403 m d a t o u t p u t d r i v e r i s a sle w r a t e li m i t e d d r i v e r . t his d r iv e r lo w e r s e le c t r o m a gn e t i c e m i ssi o n s, t h u s m in im izi n g el ec t r o m a g n et i c i n t er f er en c e , b o t h c o n d u c t e d a n d r adi a t e d. 65535 58368 specifi e d rang e anal o g i np ut adc co de 7168 ?320mv ?250mv + 250mv + 320mv 0 12196-023 a b 300? v i n? a b b b 300? v i n+ 1. 9p f 1. 9p f a a m cl ki n 12196- 024 r e v. 0 | p a ge 14 o f 20
data sheet AD7403 appl i ca t i ons i nfo rm a t io n c u r r e nt s e ns i ng a ppl i c at i o n s t he a d 7403 i s i d e a ll y su i t e d f o r c u r r e n t s e n si n g a p p li c a t i o n s w h e r e t h e v o l t a g e a c r o ss a sh u n t r e si st o r (r s h u n t ) i s m on i t or e d . t h e lo a d c u r r e n t f lo w i n g t h r o u g h a n e x t e r n a l sh u n t r e si st o r p r o d u c e s a v o l ta g e a t th e i n p u t t e r m in a l s o f t he a d 7403 . t he a d 7403 p r o vi d es i s o l a t i o n b et w een t h e a n a l o g i n p u t f r o m t h e c u r r e nt s e n si n g r e si st o r a n d t h e d i g i t a l o ut p ut s . b y s e l e c t i ng t he a p p r o p r i a t e s h u n t r es i s t o r va l u e, a va r i et y o f c u r r en t r a n g es c a n b e m on i t or e d . ch o os i n g r s hu nt t h e sh u n t r e si st o r (r s h u n t ) va l u es u s ed i n c o n j u n c t i o n w i t h t h e a d 7403 a r e d et er m i n ed b y t h e s p ec i f i c a p p l i c a t i o n r eq u i r em en t s i n t er m s o f vo l t a g e, c u r r e n t , a n d p o w e r . s m a ll r e s is t o r s m in im ize p o w e r d is s i p a t io n , w he re a s l o w i n du c t an c e r e si st o r s p r e v e n t a n y i n d u c e d v o l t a g e sp i k e s, a n d g o o d t o le r a n c e d e vi c es r ed u c e c u r r en t va r i a t i o n s . t h e f i n a l va l u es c h o s en a r e a c om p r om i s e b e t w e e n l ow p ow e r d i s s i p a t i on a n d a c c u ra c y . h i g h er va l u e r es i s t o r s u s e t h e fu l l p e r f o r m a n ce i n pu t r a n g e o f t h e a d c , t h u s ac h i e v i n g max i m u m s nr p e r f o r ma n c e . l o w v a l u e r e si st o r s d i ssi p a te l e s s p o w e r b u t d o n o t u s e t he f u ll p e rf orm a n c e i n p u t ra n g e . t he a d 7403 , h ow e v e r , d e li v e r s e x ce l l e n t p e r fo r m a n ce , e v e n w i t h lo w e r i n p u t si gn a l le v e ls , a llo w i n g lo w v a l u e sh u n t r e si st o r s t o b e u s e d w hil e m a in t a i n in g s y s t e m p e rf orm a n c e . to choose a su i t a b le sh u n t r e si st o r , f i r s t d e te r m i n e th e c u r r e n t t hr o u g h t he s h u n t . t h e s hu nt c u r r e nt f o r a 3 - p ha s e in d u c t io n mo t o r c an b e e x p r e ss e d as pf ef v p i w r ms = 73 . 1 w h er e: i r m s is the m o t o r p h a s e c u rr e n t ( a rm s ) p w is the m ot or p ow e r ( wa t t s) v is the m ot or s up p l y v o l t a ge (v ac ) ef is the m ot or e f f i c i e n c y (% ) pf is the p o w er ef f i c i en c y (% ) t o d et er m i n e t h e s hu nt p e a k s en s e c u r r e n t , i s e n s e , c on s i d e r t h e mo t o r p h as e c u r r e n t a n d a n y o v e r lo ad t h a t ma y b e p o ssi b le i n th e s y ste m . w h en t h e p ea k s en se c u r r en t i s k no w n, di v i de t he v o lt a g e r a n g e o f t h e a d 7403 ( 250 m v ) b y t h e p e ak s en s e c u r r e n t t o y i e ld a max i m u m s h u n t v al u e . i f the p o w e r d is s ip a t io n in the s h u n t r e s is t o r is to o l a r g e , the sh u n t r e si st o r c a n b e r ed u c ed a n d le ss o f t h e a d c i n p u t r a n g e ca n be us e d . f i g u re 25 s h o w s t h e si n a d p e r f o r m a n ce ch a r a c t e r i s t i cs an d t h e e n ob of r e s ol u t i on f or t h e a d 7403 f o r d i f f e re n t i n p u t si gn a l a m p li t u d e s. f i g u re 26 s ho w s the r ms n oi s e p e r f orm a n c e f or dc i n p u t si gn a l a m p li t u d e s . t he a d 7403 p e rf orm a n c e a t lo w e r i n p u t s i gn a l r a n g e s a llo w s sm a lle r sh u n t v a l u e s t o b e u s e d w hil e s t il l m a i n t a in i n g a hig h l e v e l o f p e r f orm a n c e a n d o v e ra l l sy st em ef f i c i en c y . f ig u re 2 5 . s i na d v s . v in + a c i n pu t si g n a l a m pl i t u de f ig u re 2 6 . r m s no is e v s. v in + dc i n p u t s ig n a l a m p lit u d e r s h u n t m u st b e a b le t o d i ssi p a t e t h e i2r p ow e r lo ss e s. i f t h e p o w er d i ssi p a t i o n r a t i n g o f t h e r es i st o r i s ex c eed ed , i t s v a l u e ma y dr i f t o r t h e r e si st o r ma y b e da mag e d, r e su l t i n g i n a n o p e n c ir c u it . t his o p e n c ir c u it c an r e su l t i n a di f f e r e n t i al v o lt ag e a c r o ss t h e t e r m i n a ls o f t h e a d 7 403 , i n ex c es s o f t h e a b s o lu t e m a x i m u m r a t i n gs. i f i s e n s e ha s a l a r g e hig h f r e q u e n c y c o m p o n e n t, c h o o s e a r e si sto r wi th l o w i n d u c ta n c e . v o l ta g e s e n s i ng a ppl i c at i o n s t he a d 7403 c a n al s o b e u s e d f o r i s o la t e d v o l t ag e mo n i t o r i n g . f o r e xa m p l e , i n m o t or c o n t ro l a p p l i c a t i o n s , i t c a n b e u s e d to s en s e t he b u s v o l t a g e . i n a p p li c a t i o n s w h e r e t h e v o lt a g e b e i n g m on i t or ed ex c eed s th e s p ec i f i ed a n a l o g i n p u t r a n g e o f t h e a d 7403 , a v o l t a g e d i vi d er n et w o r k c a n b e u s ed t o r ed u c e t h e v ol t a g e b e i ng m on i t or e d t o t h e r eq u i r ed r a n g e. 60 65 70 75 80 85 90 0 50 100 150 200 250 sinad (db) v in+ ac input signa l amplitude (mv) 14 -bit enob 11-bit enob 12-bit enob 13-bit enob 12196-025 f in = 1khz t a = 25 c m cl ki n = 20m hz v dd1 = 5v v dd2 = 5v 0 0. 2 0. 4 0. 6 0. 8 1. 0 1. 2 1. 4 1. 6 ?320 ?240 ?160 ?80 0 80 160 240 320 r ms n o i se (l sb ) m cl ki n = 5 m h z m cl ki n = 1 0 m h z m cl ki n = 2 0 m h z v i n+ dc i np ut s i g na l a mpl i t u d e (mv) d c i n p u t 100 k s am p l es p er d a t a p o i n t 12196-026 re v. 0 | p a ge 15 o f 20
AD7403 data sheet i npu t fi l te r in a t y p i c al us e ca s e f o r di r e c t l y me as u r i n g t h e v o l t ag e ac r o s s a sh u n t r e si st o r , t he a d 7403 c a n b e c o nne c t e d d i r e c t l y a c r o s s t h e sh u n t r e si st o r w i t h a si m p le r c l ow - p a ss f i l t e r on e a c h i n p u t . t h e r ec o m m en d ed c i r c u i t c o n f i g u r a t i o n f o r d r i vi n g t h e d i f f e r e n t i a l i n p u t s t o a c h i e v e b e s t p e r f o r m a n c e i s s h o w n i n f i g u re 27 . a n rc l ow - pa s s f il t e r is p l a c e d o n b ot h t h e a n a l og i np u t p i ns . r e c o m m e n d e d v a l u e s f or t h e r e s i s t ors a n d c a p a c i t o r s a re 10 ? a n d 220 p f , r e sp e c t i v e ly . i f p o ssi b le , e q u a li z e t h e s o u r c e im p e d a n c e o n e a c h a n a l o g in p u t t o m in im i ze o f f s e t . f ig u re 2 7 . r c l ow - pass f ilt er i n p u t net w o rk t he in p u t f il t e r c o n f i g u ra t i o n f or t h e a d 7403 i s n o t li m i te d to t he l ow - p a ss str u c t u r e s h o wn i n f i g u re 27 . t he d i f fe r e n t i a l rc f i l t e r c o nf i g u r a t io n s ho w n in f i g u re 28 al so ac h i e v e s ex c el l en t p e rf o rm a n c e . r ec o m m en d ed va l u es f o r t h e r es i st o r s a n d ca pa ci t o r a r e 22 ? an d 47 p f , r e sp e c t i v e ly . f ig u re 2 8 . dif f eren t ia l r c f ilt er n et w o r k f i g u re 29 c o m p a r es t h e t y p i c a l p er f o r m a n c e f o r t h e i n p u t f i l t er st r u c t u r e s o u t li n e d i n f i g u re 27 an d f i g u re 28 f or d i f fe r e n t r e s i s t or a n d c a p a c i t or va l u es . f ig u re 2 9 . s nr v s. d ecim a t io n r a t e f o r dif f eren t f ilt er s t ru ct u res f o r dif f e ren t r e si stor an d c ap ac i tor v al u e s d i g i t al f i lt e r t h e ou t p u t of t h e a d 7403 i s a c o n t i n u o u s d i g i ta l bi t s t r e am . to re c o n s t r u c t t h e o r i gi n a l i n p u t si gn a l i n f o r m a t i o n , t h i s o u t p u t bi t s t re a m n e e ds t o b e di g i t a lly f i l t e r e d a n d de c i ma t e d. a s in c f il t e r i s r e c o mme n de d d u e t o i t s si m p li c i t y . a s in c 3 f il t e r is r e c o mme n de d b ec a u s e i t i s on e o r d e r h ig he r t h a n t ha t o f t he a d 7403 m o d ul a t o r , wh ic h i s a s e c o nd - ord e r m o d u l a t o r . t he t y p e o f f i l t e r s e l e c t e d , t h e d e c i m a t i o n r a t e , an d t he m o d u la t o r c lo c k us e d d et er m i n es t h e o v e r a ll sy st e m r e s o l ut i o n a n d t h r o ug h p u t r a t e . t he hig he r the d e c im a t io n ra t e , the g r e a t e r t h e sy st e m a c c u r a c y , a s i l l u s tr at e d i n f i g u re 30 . h o w e v er , t h er e i s a t r a d e - o f f b et w een a c cu r a cy a n d t hr o u g h p u t ra t e a n d , the r e f o r e , hig he r d e c im a t io n r a te s r e su l t i n l o w e r th r o u g h p u t s o l u ti o n s. n o te th a t f o r a g i v e n ba n d w id t h r e q u ir e m e n t , a hig he r m c l ki n f r e q u e n c y c a n a l l o w hig he r d e c im a t io n ra t e s to b e u s e d , r e s u l t in g in h ig he r s n r p e rf orm a n c e . f ig u re 3 0 . s nr v s. d ecim a t io n r a t e f o r dif f eren t s in cx f ilt er o rd ers a s i n c 3 f i l t er i s r e c o m m en d ed f o r u s e w i t h t h e a d 7403 . t his f i l t er c a n b e i m p lem en t ed o n a f i e l d p r o g r am m ab l e g a t e ar r ay ( f pga ) or a di g i t al si gn a l pr o c e ss o r ( d sp ) . e q u a t i o n 1 d e s c ri b e s th e t ra n s f e r f u n c t i on of a s i n c f i l t e r . ( ) ( ) n dr z z dr z h ? ? ? ? ? ? ? ? ? ? = ? ? 1 1 1 1 ) ( (1 ) w h er e dr is t he d e c im a t io n r a t e a n d n is the s in c f il t e r o r d e r . t h e th r o u g h p u t r a te o f t he s in c f il t e r is d e t e r m in e d b y the m o d u l a t o r c l o c k a n d t he d e c im a t io n r a t e s e l ec t ed . dr mclk throughput = (2 ) w h er e mc l k is t he m o d u l a t o r c l o c k f r e q u e n c y a s t h e d ec i m a t i o n r a t e i n c r ea s es , t he d a t a o u t p u t s ize f r o m the s in c f il t e r in c r e a s e s. t he o u t p u t d a t a s ize is e x p r e s s e d in e q u a t i o n 3 . t h e 1 6 m o st si gn i f i c a n t b i t s a r e u s e d t o r e t u rn a 16 - b i t re s u l t . d at a s i z e = n l og 2 dr (3 ) r v in? r v in+ c c AD7403 12196- 027 r v in? r v in+ c a d 7403 12196- 028 50 55 60 65 70 75 80 85 90 95 10 100 1000 snr (db) decim a tion r a te l o w p as s , ? , 22 0p f d i f f e r e n t i a l , ? , 47 p f di f f e re n t i a l , ? , 10 n f 12196-029 f in = 1khz 0 10 20 30 40 50 60 70 80 90 100 10 100 1000 s nr ( d b) de ci m a tion r a te s i n c 1 s i n c 2 s i n c 3 s i n c 4 12196- 030 f in = 1khz r e v. 0 | p a ge 16 o f 20
data sheet AD7403 fo r a s i n c 3 f i l t e r , t he ? 3 d b f i l t er r es p o n s e p o i n t c a n b e d er i v ed f r o m th e f i l te r tr a n s f e r f u n c ti o n , e q u a ti o n 1 , a n d i s 0. 262 t i m e s t he t h r o u g h pu t r a t e . t he f il t e r c ha r a c t e r is t i c s f o r a t h i rd - o rd e r s in c f il t e r a r e s u m m a r i ze d in ta b l e 11 . tabl e 11 . s in c 3 f i l t e r c h a ra c t e ri s t i c s f o r 2 0 m h z m c l k i n d e c im a tio n r a tio (d r ) t hr o u g hp u t r at e (k h z ) o u tp u t d a ta s i ze ( b it s) f i lt er r es p o n s e ( kh z ) 32 625 15 163. 7 64 312. 5 18 81. 8 128 156. 2 21 40. 9 256 78. 1 24 20. 4 512 39. 1 27 10. 2 t h e f o llo w i n g v e r i lo g c o d e p r o v i d e s a n e x a m p le o f a si n c 3 f i l t e r im p l e m e n t a t i o n o n a x il in x ? s p a r t a n ? - 6 f pga . n o te th a t th e da t a i s r e ad o n t h e p o s i t i v e c l o c k e dg e . i t i s r e c o mme n de d t o r e ad i n t h e da t a o n t h e p o s i t i v e c l o c k e dg e . t he c o d e is c o n f i g ur a b l e t o a c c o m m o d a t e d e c i m a t i o n r a t e s f r o m 32 t o 4096. module dec256sinc24b ( input mclk1, /* used to clk filter */ input reset, /* used to reset filter */ input mdata1, /* i nput data to be filtered */ output reg [15:0] data, /* filtered o utput */ output reg data_en, input [15:0] dec_rate ); /* data is read on positive clk edge */ reg [36:0] ip_data1; reg [36:0] acc1; reg [36:0] acc2; reg [36:0] acc3; reg [36:0] acc3_d2; reg [36:0] diff1; reg [36:0] diff2; reg [36:0] diff3; reg [36:0] diff1_d; reg [36:0] diff2_d; reg [15:0] word_count; reg word_clk; reg enable; /*perform the sinc action */ always @ (mdata1) if(mdata1==0) ip_data1 <= 37'd0; /* change 0 to a -1 for twos complement */ else ip_data1 <= 37'd1; /*accumulator (integrator ) perform the accumulation (iir) at the speed of the modulator. z = one sample delay mclkout = modulators conversion bit rate */ f ig u re 3 1 . a ccu m u la t o r always @ (negedge mclk1, posedge reset) begin if (reset) begin /* initialize acc registers on reset */ acc1 <= 37'd0; acc2 <= 37'd0; acc3 <= 37'd0; end else begin /*perform accumulation process */ acc1 <= acc1 + ip_data1; acc2 <= acc2 + acc1; acc3 <= acc3 + acc2; end end /*decimation stage (mclkout/word_clk) */ always @ (posedge mclk1, posedge reset) begin if (reset) word_count <= 16'd0; else begin if ( word_count == dec_rate - 1 ) word_count <= 16'd0; else word_count <= word_count + 16'b1; end end always @ ( posedge mclk1, posedge reset ) begin if ( reset ) word_clk <= 1'b0; else begin if ( word_count == dec_rate/2 - 1 ) word_clk < = 1'b1; else if ( word_count == dec_rate - 1 ) word_clk <= 1'b0; end end /*differentiator (including decimation stage) perform the differentiation stage (fir) at a lower speed. m cl ki n i p _d at a1 acc1+ acc2+ acc3+ + z + z + z 12196- 031 r e v. 0 | p a ge 17 o f 20
AD7403 data sheet z = one sample delay word_clk = output word rate */ f ig u re 3 2 . dif f eren t ia t o r always @ (posedge word_clk, posedge reset) begin if(reset) begin acc3_d2 <= 37'd0; diff1_d <= 37'd0; diff2_d <= 37'd0; diff1 <= 37'd0; diff2 <= 37'd0; diff3 <= 37'd0; end else begin diff1 <= acc3 - acc3_d2; diff2 <= diff1 - diff1_d; diff3 <= diff2 - diff2_d; acc3_d2 <= acc3; diff1_d <= diff1; diff2_d <= diff2; end end /* clock the sinc output into an output register word_clk = output word rate */ f ig u re 3 3 . c lo ck in g s in c3 o u tp u t i n to an o u tp u t r e g i ste r always @ ( posedge word_clk ) begin case ( dec_rate ) 16'd32:begin data <= (diff3[15:0] == 16'h8000) ? 16'hffff : {diff3[14:0], 1'b0}; end 16'd64:begin data <= (diff3[18:2] == 17'h10000) ? 16'hffff : diff3[17:2]; end 16'd128:begin data <= (diff3[21:5] == 17'h10000) ? 16'hffff : diff3[20:5]; end 16'd256:begin data <= (diff3[24:8] == 17'h10000) ? 16'hffff : diff3[23:8]; end 16'd512:begin data <= (diff3[27:11] == 17'h10000) ? 16'hffff : diff3[26:11]; end 16'd1024:begin data <= (diff3[30:14] == 17'h10000) ? 16'hffff : diff3[29:14]; end 16'd2048:begin data <= (diff3[33:17] == 17'h10000) ? 16'hffff : diff3[32:17]; end 16'd4096 :begin data <= (diff3[36:20] == 17'h10000) ? 16'hffff : diff3[35:20]; end default:begin data <= (diff3[24:8] == 17'h10000) ? 16'hffff : diff3[23:8]; end endcase end /* synchronize data output*/ always@ ( posedge mclk1, posedge reset ) begin if ( reset ) begin data_en <= 1'b0; enable <= 1'b1; end else begin if ( (word_count == dec_rate/2 - 1) && enable ) begin data_en <= 1'b1; enable <= 1'b0; end else if ( (word_count == dec_rate - 1) && ~enable ) begin data_en <= 1'b0; enable <= 1'b1; end else data_en <= 1'b0; end end endmodule wo r d_cl k ac c3 dif f1 di f f3 + ? + ? di f f2 z ?1 ? + ? z ?1 z ?1 12196- 032 w o rd_cl k d at a diff3 12196-033 rev. 0 | page 18 of 20
data sheet AD7403 i nte r fa c i ng to a ds p - cm 4 0 x f t he a d sp - c m 40x f fa m i l y o f m i x e d - si gn a l c o n t r o l p r o c e ss o r s c o nt a i n s on - ch i p s in c f i l t e r a n d c l o c k g e n e ra t i o n m o d u l e s f or d i r e c t c o n n e c ti o n to th e a d 7403 mc l k i n a n d m d a t pi n s . t he a d sp - c m 40x f ca n p r o ce s s b it s t r e a m s f r om f ou r a d 7403 d e v i c e s us i n g a p a i r o f c o n f i g ur a b l e s i n c f i l t e rs f or e a c h b i t s t r e am . t he p r im a r y s i nc f i l t er o f ea c h p a i r p r o d u c es t h e f i l t er ed a n d d e c i m a te d o u t p u t f o r th e p a i r . t h e o u t p u t c an b e d ec i m a t ed t o a n y i n t eg er r a t e b et w een 8 a n d 2 5 6 t i m es l o w er t h a n t h e i n p u t r a t e. t h e f o u r s ec o n d a r y s in c f i lt e r s a r e l ow l a te n c y f i l te r s wi th p r o g r a m m a b l e p o s i t i v e a n d n eg a t i v e o v e r r a n g e d et ec t i o n c o m p a r a to r s th a t c a n b e u s e d to d e te c t s y s t e m f a u l t c o n d i ti o n s f i g u re 34 s h o w s t h e t y p i c a l i n t er f a c e b et w een t h e a d 7403 an d t he a d sp - c m4 0 x f . a d d i t i o n a l inf o r m a t io n o n t h e c o nf i g u r a t io n of t h e s in c f i l t er m o d u l es i n t h e a d sp - c m 40x f c a n b e f o u nd i n an - 1265 . f ig u re 3 4 . i n t erf a cin g t h e a d 7 4 03 to t h e a ds p - c m 40 x f g r o u nd i ng a nd l a yo u t i t i s r e c o mme n de d t o d ec o u p le t h e v dd 1 su ppl y wi th a 10 f ca pa ci t o r i n pa r a l l e l w i t h a 1 nf ca pa ci t o r t o gn d 1 . d e c o u pl e pi n 1 a n d pi n 7 in d i v id u a l l y . de c o u p l e th e v dd2 s u ppl y wit h a 100 n f va l u e t o gn d 2 . i n a p p l ic a t io n s in v o l v in g h ig h c o m m o n - m o d e t r a n si e n t s, e n su r e t h a t b o a r d c o u p l i n g a c r o ss t h e i s o la t i o n ba r r ie r is m in im ize d . f u r t he r m o re , d e si gn t h e b o ar d l ay o u t s o t h a t a n y c o u p li n g t h a t o c c u r s e q u a lly a f f e c t s a l l p i n s o n a gi v e n co m p o n en t s i d e. f a i l u r e t o en su r e e q u a l c o u p li n g c an c au s e vo l t a g e d i f f er e n t i a l s b et w een p i n s t o e x c e ed t h e a b so l u t e m a x i m u m r a t i n gs o f t h e d e v i c e , t h er eb y l ea d i n g t o l a t c h - u p or p e rm a n e n t d a m ag e . pl a ce a ny d e c o u p l i n g u s e d as cl o s e t o t h e s u ppl y pi n s a s p o ssi b le . m in im ize s e r i e s r e si st a n c e i n t h e a n a lo g i n p u t s t o a v o i d a n y d i st o r t i o n e f f e c t s, e sp e c i a lly a t h i g h t e m p e r a t u r e s. i f p o ssi b le , eq u a l i z e t h e so u r c e i m p e d a n c e o n ea c h a n a l o g in p u t t o m in i m iz e o f fs e t . c h e c k fo r m i sm a t c h a n d t h e r m o c o up le e f f e c t s o n t h e a n a lo g i n pu t p r i n t e d c i rc u i t b o a rd ( pc b ) t r a ck s t o r e d u ce o f fs e t d r i f t . in s u l a t io n l if e t ime a ll i n su la t i o n st r u c t u r e s e v e n t u a ll y b r e a k d o w n w h e n su b j ec t ed t o v o lt a g e st r e ss o v e r a su f f i c i e n t l y lo n g p e r i o d . t h e r a t e o f in s u l a t i o n d e g r a d a t io n is d e p e n d e n t o n t he c ha r a c t e r is t ic s o f t h e v o lt ag e w a v e f o r m a p p li e d ac r o ss t h e i n su l a t i o n . i n addi t i o n t o t h e t es t i n g p er f o r m ed b y t h e r eg u l a t o r y a g en c i es , an a lo g d e vi c es c a r r i es o u t a n ex t en s i v e s et o f e v a l u a t i on s to d e t e rm i n e t he l if e t im e o f the i n s u l a t io n s t r u c t u r e w it hin t he a d 7403 . a n a lo g d e v i c e s p e r f o r m s a c c e le r a t e d li f e t e st i n g u si n g v o l t a g e l e v e l s hig he r tha n the ra t e d c o n t in u o u s w o r ki n g v o l t a g e . a c c e l e ra t i on f a c t o rs f o r s e v e ra l o p e ra t i n g c o n d i t i o n s a r e d e te r m i n e d . t h e se f a c to r s a l l o w c a lc u l a ti o n o f th e ti m e to f a i l u r e a t t he a c t u a l w o r ki ng v o l t a g e . t he v a l u e s s ho w n i n ta b l e 8 su m m a r i z e t h e p ea k vo l t a g e f o r 20 y ea r s o f s er vi c e l i f e f o r a b i p ol a r , ac o p e r a t i n g c o n di t i o n a n d t h e max i m u m v d e a p p r ov e d w or k i n g v ol t a g e s. t h e s e t e st s su b j e c t ed t he a d 7403 t o c on t i n u o u s c ros s i s ol a t i on v o lt a g es . t o a c c el er a t e t h e o c c u r r en c e o f f a i l u r es , t h e s el ec t ed te st v o l ta g e s w e re va l u es ex c eed i n g th os e o f n orm a l u s e . t h e ti m e to fa i l u r e va l u es o f t h es e u n i t s w e re r e c o r de d a n d u s e d t o c a lc u la t e t he a cce le r a t i o n fa c t o r s. t h e s e fact o r s w e re t h en u s ed to c a lc u la te th e ti m e t o f ai l u r e u n de r t he n o rma l op e ra t i n g c o n d it io n s. t he v a l u e s s ho wn in ta b l e 8 a r e t h e l es ser o f t h e f o llo w i n g t w o v a l u e s: ? t h e va l u e t h a t en su r es a t l ea st a 20 - ye a r l i f e t i m e of c o nt i nu o u s u s e . ? t h e max i m u m v d e a p p r o v e d w o r k i n g v o l t ag e . n o t e th a t th e l i f e ti m e o f th e a d 7403 va r i es a cco r d i n g t o t h e wa v e f o r m t y p e im p o s e d a c r o s s t he is o l a t i o n ba r r ie r . t he i c o u p le r i n su la t i o n st r u c t u r e i s st r e ss e d d i f f e r e n t l y , de p e n di n g o n w h e t h e r t h e w a v e f orm i s b i p o l a r a c , u n i p o l a r a c , or d c . f i g u re 35 , f i g u re 36 , an d f i g u re 37 i l l u s tr a te th e d i f f e r e n t i s ol a t i on v ol t a g e w a v e f or m s. f ig u re 3 5 . b ip o la r a c w a v ef o rm , 5 0 hz or 6 0 h z f ig u re 3 6 . u n ip o la r a c w a v ef o rm , 50 hz or 60 h z f ig u re 3 7 . dc w a v ef o rm sinc pair n primary seco ndary lim it c on tr ol for gr oup n mo dul at o r cl o ck n ads p - cm40xf 1 a d 7403 1 m dat m cl ki n s inc0_clk0 si nc0_d0 1 a d d ition a l p in s om itte d for c la r ity 12196- 034 0v rat e d p e ak v o l t ag e 12196-035 0v rated peak voltage 12196-036 0v rated peak voltage 12196-037 rev. 0 | page 19 of 20
AD7403 data sheet out l i ne di m ensi o ns f ig u re 3 8 .1 6 - l ea d s t a n d a rd s m a ll o u t lin e p a ck a g e, w it h i n crea s ed c reep a g e [ so i c_ i c] w id e b o d y ( r i - 1 6 - 2) dim en s io n s s h o w n in m illim et ers or de r i n g g u i de mo d e l 1 t em p e r a t u r e r an g e p a ck a ge d e s cr i pt i o n p ac k ag e o p tio n AD7403 briz ?40c to +125c 16 - lead standard small outline package , with increased creepage [soic_ic] ri - 16 - 2 AD7403briz - rl7 ?40c to +125c 16 - lead standard small outline package, with increased creepage [soic_ic] ri - 16 - 2 AD7403briz - rl 13 ?40c to +125c 16 - lead standard small outline package, with increased creepage [soic_ic] ri - 16 -2 1 z = r oh s com p l i a n t p a r t . 1 1-15-20 1 1- a 16 9 8 1 se a ting plane co p l anari t y 0. 1 1.27 bsc 12. 85 12. 75 12.65 7. 60 7. 50 7.40 2.64 2.54 2.44 1. 01 0. 76 0.51 0. 30 0. 20 0.10 10. 51 10. 31 10. 1 1 0. 46 0.36 2.44 2.24 p in 1 m ark 1.93 ref 8 0 0. 32 0. 23 0. 71 0. 50 0.31 45 0. 25 bs c ga ge p l ane compliant t o jedec s t andards ms-013-ac ? 2014 analog devices, inc. all rights reserved. trademarks and reg i s t e red t rad em a rk s are t h e p ro p ert y o f t h ei r res p ec t i v e o w n ers . d 1 21 96 - 0- 4/ 1 4(0 ) re v. 0 | p a ge 20 o f 20

▲Up To Search▲

Price & Availability of AD7403

	To Download AD7403 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .