technical data low power ground fault interrupter IL4145A ordering information IL4145An pl ast i c dip IL4145Ad soic t a = -35 to 8 5 c for all packages . the IL4145An i s a l o w power cont rol l e r for ac out l e t ground faul t interrupters. these devices detect hazardous grounding conditions, such as equi pm ent (connect ed t o opposi t e phases of t h e ac l i n e) i n cont act wi t h a pool of wat e r and open ci rcui t s t h e l i n e before a harm ful or l e t h al shock occurs. c ont ai ned i n t e rnal l y are a 26v zener shunt regul at or, an op am p, and an sc r dri v er. w i t h t h e addi t i on of t w o sense t r ansform e rs, a bri dge rect i f i e r, an scr, a relay, and a few additional com ponents, the IL4145An will det ect and prot ect agai nst bot h hot wi re t o ground and neut ral wi re t o ground faul t s . the si m p l e l a y out and convent i onal desi gn ensure ease of application and long-term reliability. ? no pot ent i o m e nt er requi red ? direct interface to scr ? suppl y vol t a ge deri ved from ac l i n e ? 26v shunt ? ad j u stab le sen s itiv ity ? grounded neut ral faul t det ect i on ? m eet s u.l. 943 st andards ? 450 a qui escent current ? ideal for 120 v or 220 v sy st em s block diagram + ++ r1 +in p ut v fb v re f +v s (+ 13v ) (+ 26v ) o p a m p o u tp ut sc r t r i g ge r g r ou nd 6.5 v 6. 5 v 6. 5 v 6. 5 v r2 r3 10k 10 k 4. 7k pin assignment 1 2 3 4 nc 8 7 6 5 gn d +v s v re f +in p ut v fb op am p ou t p ut s cr t r i g g e r absolute maximum ratings s y m b o l p a r a m e t e r v a l u e u n i t i cc suppl y c u rrent 18 m a p d int e rnal power di ssi pat i on 500 m w tst g st orage tem p erat ure r a nge -65 t o +150 c topr operat i ng tem p erat ure r a nge -35 t o +85 c t j junct i on tem p erat ure 125 c t l lead tem p erat ure 125 c t a < 50c 450 m w p d for t a > 50c derat e at 6 m w / c
IL4145A electrical characteristics (i s = 1.5 m a and t a = +25c) s y m b o l p a r a m e t e r test condition min max unit v oh det ect or r e ference vol t a ge pi n 7 t o pi n 3 6.8 8.1 v shunt regulator +v s zener vol t a ge pi n 6 t o pi n 4 2 5 2 9 . 2 v v ref r e ference vol t a ge pi n 3 t o pi n 4 1 2 . 5 1 4 . 6 v i s qu iescen t cu rren t +v s = 24 v 7 5 0 a operational amplifier v io offset vol t a ge pi n 2 t o pi n 3 -3.0 +3.0 m v v d +out put vol t a ge swi ng pi n 7 t o pi n 3 6.8 8.1 v v ol ?out put vol t a ge swi ng pi n 7 t o pi n 3 -13.5 -9.5 v i oh +out put source c u rrent pi n 7 t o pi n 3 ? -450 ? ? -850 ? a i ol ?out put source c u rrent pi n 7 t o pi n 3 800 1200 a b w gai n b a ndwi d t h product f = 50 khz 1.0 m h z resistors i s = 0 ma r 1 r 1 pi n 1 t o pi n 3 8 12 k ? r 2 r 2 pi n 2 t o pi n 3 8 12 k ? r 3 r 3 pi n 5 t o pi n 4 3.5 5.9 k ? scr t r i gger vol t age pi n 5 to pi n 4 v on detector on 1.5 v v off detector off 0 1 0 m v electrical characteristics (i s = 1.5 m a and -35c t a +85c ) s y m b o l p a r a m e t e r test condition min max unit v oh det ect or r e ference vol t a ge pi n 7 t o pi n 3 6.5 8.3 v shunt regulator +v s zener vol t a ge pi n 6 t o pi n 4 24 3 0 v v ref r e ference vol t a ge pi n 3 t o pi n 4 12 1 5 v i s qu iescen t cu rren t +v s = 23 v 8 0 0 a operational amplifier v io offset vol t a ge pi n 2 t o pi n 3 -5.0 +5.0 m v v d +out put vol t a ge swi ng pi n 7 t o pi n 3 6.5 8.3 v v ol ?out put vol t a ge swi ng pi n 7 t o pi n 3 -14 -9 v resistors i s = 0 ma r 1 r 1 pi n 1 t o pi n 3 7.5 12.5 k ? r 2 r 2 pi n 2 t o pi n 3 7.5 12.5 k ? r 3 r 3 pi n 5 t o pi n 4 3.5 5.9 k ? scr t r i gger vol t age pi n 5 to pi n 4 v on detector on 1.3 v v off detector off 0 5 0 m v
IL4145A principles of operation the 26v shunt regul at or vol t a ge generat e d by t h e st ri ng of zener di odes i s di vi ded i n t o t h ree reference vol t a ges: 3/ 4 vs , 1/ 2 vs , and 1/ 4 vs . vr ef i s at 1/ 2vs and i s used as a reference t o creat e an art i f i cal ground of +13v at t h e op am p noni nvert i ng i nput . fig u r e 1 sh o w s a t h ree-wi re 120v ac out l e t gfi appl i cat i on usi ng an IL4145An. faul t si gnal s from t h e sense t r ansform e r are ac coupl ed i n t o t h e i nput and are am plified according to the following equation: v7 = rsense x isense/n w h ere v7 i s t h e r m s vol t a ge at pi n 7 rel a t i v e t o pi n 3, rsense is th e v a lu e o f th e feedback resistor connected from pi n 7 t o pi n 1, isense i s t h e faul t current i n am ps rms an d n is th e tu rn s ratio o f th e tran sfo r m e r. w h en v7 exceeds plus or m i nus 7.2v relative to pin 3 the scr trig g e r o u t p u t will g o h i g h an d fire th e ex tern al scr. the form ula for v7 is approxim a te because it does not include the sense transf orm e r characteristics. grounded neutral fault detection is accom p lished when a short or faul t cl oses a m a gnet i c pat h bet w een t h e sense t r ansform e r and t h e grounded neut r a l t r a n s f o r m e r . t h e r e s u l t a n t a c c o u p l i n g clo s es a p o s itiv e feed b ack p a th around the op am p, and therefore the op am p oscillates. w h e n t h e p e a k s o f the oscillation voltage exceed the scr trig g e r co m p arato r th resh o l d s , th e scr o u t p u t will go hi gh. shunt regulator r l ine l i m i t s t h e current i n t o t h e shunt regul at or; 220v ap p licatio n s will req u i re su b s titu tin g a 4 7 k ? 2w r e sist or. in addi t i on t o suppl y i ng power t o t h e ic , t h e s h u n t regul at or creat es i n t e rnal reference vol t a ges (see above). operational amplifier rsense is a feedback resistor that sets gain and th erefo r e sen s itiv ity to n o r m a l fau lts. to ad j u st r s ense, fol l o w t h i s procedure: appl y t h e desi red faul t current (a di fference i n current of 5m a i s t h e ul 943 standard). ad j u st rsense u p w ard u n til th e scr activ ates. a fix e d resistor can be used for rsense, since the resultant 15% variation in sensitivity will m eet ul?s 943 4-6m a speci fi cat i on wi ndow. the rol l - off frequency i s great er t h an t h e grounded n e u t ral fau lt o s cillatio n freq u e n c y, in o r d e r to p r eserv e loop gain for oscillation (whi ch is determ ined by the i nduct a nce of t h e 200: 1 t r ansform e r and c 4 ). the senst i v i t y t o grounded neut ral faul t s i s adjust ed by ch an g i n g th e freq u e n c y o f o s cillatio n . in creasin g th e frequency reduces the sensitiv ity by reducing the loop g a in o f th e p o s itiv e feed b ack circu it. as freq u e n c y i n creases, t h e si gnal becom e s at t e nuat e d and t h e l oop g a in d ecreases. w ith th e v a lu es sh o w n th e circu it will det ect a grounded neut ral faul t havi ng resi st ance of 2 ? ?or less. the i nput t o t h e op am p are prot ect ed from overvol t a ge by back-t oback di odes. scr driver the sc r used m u st have a hi gh dv/ d t rat i ng t o ensure that line noise (generated by noisy appliances such as a d r ill m o to r) d o e s n o t falsely trig g e r th e scr. also , th e sc r m u st have a gat e dri v e requi rem e nt of l e ss t h an 200a. c f is a n o i se filter cap acito r th at p r ev en ts n a rro w pulses from firing the scr. the rel a y sol e noi d used shoul d have a 3m s or l e ss response t i m e i n order t o m eet t h e ul 943 t i m i ng requi rem e nt . sense transformers and cores the sense and grounded neut ral t r ansform e r cores are u s u a lly fab r icated u s in g h i g h p e rm eab ility lam i n a ted steel rings. their single turn prim ary is created by passi ng t h e l i n e and neut ral wi res t h rough t h e cent e r of i t s core. the secondary i s usual l y from 200 t o 1500 tu rn s. two - wire applica t io n circuit fi gure 2 shows t h e di agram of a 2-wi re 120v ac out l e t gfi ci rcui t usi ng an IL4145An. thi s ci rcui t i s not desi gned t o det ect grounded neut ral faul t s . thus, t h e grounded neut ral t r ansform e r and capaci t o rs c 3 and c 4 of fi gure 1 are not used.
IL4145A 10 00: 1 ho t li n e c1 c3 c4 c2 c f q1 on s e m i mc r100 - 6 db 1 so le n o i d load lat c h ing c ont ac ts k1 1m * i l 414 5an 10 f 0. 0 1 f 0. 03 f 0. 01 f 2. 2 f 1n4 004 ( 4 ) 15k r te s t m ov r se n s e v fb +v s r li n e v re f ( + 13v ) n eut r a l pre s s to te s t 200: 1 s e ns e t r an s f or mer g r ou n d n eut r a l tr a n s f o r m e r gn d 24 k o p a m p o u t put s c r t r i gger * val u e depends on t r ansform e r charact eri s t i c s. figure 1. gfi application circuit (three-wire outlet)
IL4145A 10 00: 1 ho t li n e c1 c2 c f q1 t a g i x 0103d a db 1 so le n o i d load lat c h ing c ont ac ts k1 1m * i l 414 5an 10 f 0. 01 f 2. 2 f 1n4 004 ( 4 ) 15k r te s t m ov r se n s e v fb +v s r li n e v re f ( + 13v ) n eut r a l pre s s to te s t s e ns e t r an s f or mer gn d 24 k o p a m p o u t put s c r t r i gger * val u e depends on t r ansform e r charact eri s t i c s. figure 2. gfi application circuit (two-wire outlet)
IL4145A schematic diagram q2 1 q1 9 6. 5v q2 0 6. 5v q1 8 6. 5v q1 7 6. 5v q8 q1 5 q4 c2 10 p f r4 50 k r1 4 1. 3k r2 10 k r5 50k r6 45 0 q1 4 q23 q1 0 q16 q7 q9 c1 4 pf q5 q6 q1 2 q1 q2 (- ) (+) (1) q3 q2 2 r1 10k r1 0 6k q1 1 q1 3 (2) v fb + i np ut r9 39 k r3 4. 7k r1 3 30 k r7 25 0k (7 ) (5 ) (4 ) (3) (6) (+1 3 v ) v re f +v s (+ 26v ) gr ou nd o p a m p ou t p ut sb s t r a t e sc r t r i g g e r r1 2 7. 2 k z1 5. 6v
IL4145A n s u f f i x p l as t i c di p ( m s ? 00 1b a ) sy m b o l m i n m a x a 8. 51 10. 16 b 6. 1 7 . 1 1 c 5. 33 d 0. 36 0. 56 f 1. 14 1. 78 g h j 0 10 k 2. 92 3. 81 no t e s : l 7. 62 8. 26 1. d i m e n s i o n s ?a ?, ?b ? d o n o t i n cl u d e m o l d f l as h o r p r o t r u s i o n s . m 0. 2 0 . 3 6 m a x i m u m m o l d f l a s h o r p r o t r u s i o n s 0. 25 m m ( 0 . 010) p e r s i d e . n 0. 38 d su f f i x so i c (m s - 0 1 2 a a) sy m b o l m i n m a x a 4. 8 5 b 3. 8 4 c 1. 35 1. 75 d 0. 33 0. 51 f 0. 4 1 . 2 7 g h j 0 8 no t e s : k 0. 1 0 . 2 5 1. d i m e n s i o ns a a n d b d o no t i n c l ud e m o l d f l a s h o r p r ot r u s i on . m 0. 19 0. 25 2. m a x i m u m m o l d f l a s h o r p r o t r u s i o n 0. 15 m m ( 0 . 006) p e r s i d e p 5. 8 6 . 2 fo r a ; fo r b ? 0. 25 m m ( 0 . 010) p e r s i d e . r 0. 25 0. 5 1. 27 5. 72 d i me n s i o n , mm d i me n s i o n , mm 2. 54 7. 62 a b h c k c m j f m p g d r x 4 5 se a t i n g pl a n e 0 . 25 (0 . 0 10 ) m t -t - 1 8 4 5 l h m j a b f g d se a t i n g pl a n e n k 0 . 2 5 ( 0 .01 0 ) m t -t - c 1 8 4 5
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