Control circuit for a Self-Oscillating Power Supply (SOPS) TDA8385

Size: px

Start display at page:

Download "Control circuit for a Self-Oscillating Power Supply (SOPS) TDA8385"

Suzanna Nelson
5 years ago
Views:

1 FEATURES Bandgap reference generaor Slow-sar circuiry Low-loss peak curren sensing Over-volage proecion Hyseresis conrolled sand-by funcion Error amplifier wih gain seing Programmable ransfer characer generaor Proecion agains open- and shor-circuied feedback loop Over-load curren fold back characerisic LED driver Demagneizaion proecion Programmable deerminaion of swich-on momen of swiching ransisor for low-swiching losses Feed-forward inpu Regulaion-indicaor oupu Programmable minimum on-ime of swiching ransisor Accurae peak-curren seing. GENERAL DESCRIPTION The is inended o be used in combinaion wih he opo-coupler (CNR50) as a conrol uni for a self-oscillaing power supply. ORDERING INFORMATION EXTENDED TYPE NUMBER PACKAGE PINS PIN POSITION MATERIAL CODE 16 DIL plasic SOT38WBE March

2 BLOCK DIAGRAMS dbook, full pagewidh P GND lach curren reference seing 3 I ref REFERENCE BLOCK 2 STABILIZED SUPPLY 1 P (min) DETECTOR 28 rese (28, 27, 23) I ref ref sab SUPPLY REFERENCES I feed forward inpu 13 fo s regulaion indicaor oupu 1 RIO REGULATION INDICATOR 29 X 7 differenial amplifier oupu 11 diff mv DIFFERENTIAL AMPLIFIER ref (2.5 ) diff s 3 feedback volage inpu 9 fb 50 µa CLAMP 2.5 TCG TCG MINIMUM OLTAGE CLAMP 6 4 CONTROL PART III ransisor-on seing inpu 4 T on(min) slow sar volage inpu 7 ss 5 ss + T on (min) µa charge rese (28) quick discharge 27 SLOW START II MCD417 Fig.1 Block diagram; par A (coninued in Fig.2; par B). March

3 handbook, full pagewidh sand-by volage inpu lach sb 10 lach OUTPUT STAGE 15 LED 2 LED driver oupu 2.5 STAND-BY IX r PWM 17 sim 8 LED DRIER I I comparaor Q (23) 18 (28) S FF Q R 13 demagneizaion LED CONTROL demagneizaion c I sim 0.2 I 12 9 I peak I curren simulaion inpu peak-curren seing inpu 100 m 10 DELAY 12 SAWTOOTH GENERATOR 11 DEM 115 m II 15 6 demagneizaion inpu delay seing (17) (28) 100 µa slow discharge 21 Q R m Q FF 23 S 22 over volage over-volage proecion OER-OLTAGE PROTECTION III MCD418 Fig.2 Block diagram; par B (coninued from Fig.1; par A). March

4 PINNING SYMBOL PIN DESCRIPTION RIO 1 regulaion indicaor oupu LED 2 LED driver oupu I ref 3 curren reference seing T on(min) 4 ransisor-on seing inpu I peak 5 peak curren seing inpu DELAY 6 delay seing ss 7 slow sar volage inpu OP 8 over-volage proecion fb 9 feedback volage inpu sb 10 sand-by volage inpu diff 11 differenial amplifier oupu I sim 12 curren simulaion inpu fo 13 feed forward inpu GND 14 ground (0 ) DEM 15 demagneizaion inpu P 16 posiive supply volage handbook, 2 columns RIO 1 LED I ref T on(min) I peak DELAY ss OP MCD Fig.3 Pinning diagram. 9 P DEM GND fo I sim diff sb fb FUNCTIONAL DESCRIPTION The can be divided ino 10 funcional blocks as shown in Fig.1 and Fig.2. Block for Figs 1 and 2 BLOCK NO. I II III I I II III IX X DESCRIPTION supply references sawooh generaor conrol par pulse widh modulaor (PWM) LED conrol LED driver slow-sar circuiry over-volage proecion sand-by circui regulaion-indicaor oupu These 10 funcional blocks of Fig.1 and Fig.2 conain sub-secions numbered 1 o 28 which are cross-referenced in he following descripion. Supply references (Block I) The is inended o be used on he secondary side of he self-oscillaing power supply. I can be supplied eiher by an auxiliary winding of he ransformer or an exernal supply e.g. 50 Hz ransformer. Charging of he capacior C P (see Fig.16) akes place during ransisor on-ime (T on ; see Fig.17). During sand-by he IC is supplied by he sand-by volage sb (pin 10). The operaing volage range is from 7.5 o 20. The supply curren, inclusive drive curren for he LED, is less han 20 ma. A bandgap based reference (2.5 ) generaes a sabilized volage sab of 3.9 o supply all inernal circuis of he IC excep he LED driver. The LED driver is direcly supplied by P. The reference block generaes all he reference volages in he circui. By means of a resisor conneced o pin 3, a reference curren (I ref ) is defined. This curren is refleced several imes and is used o obain IC-independen seings e.g. T on(min) seing, delay seing, charging and discharging of slow-sar capacior C ss on pin 7 (see Fig.16). The power supply is released by he opo-coupler IC a an inpu volage level, which is high enough o guaranee correc operaion of he e.g. P = 10 by sensing he mains volage I. As soon as he SOPS swiching ransisor (T1, see Fig.16) is conducive he capacior C P is charged. As long as he IC supply volage is below 7.5 he LED driver is blocked (see lach oupu; sub-secion 28) in order o guaranee sar-up of SOPS. During he iniializaion phase he quick-discharge-swich (sub-secion 27), se inpu of flip-flop (13) and rese inpu of flip-flop (23) are also acivaed. As soon as he volage of 7.5 is reached he conrol funcions of he IC are operaive. Hyseresis on he iniializaion level is 2.3. March

5 Sawooh generaor (Block II) CURRENT SIMULATION (SEE FIGS 5 AND 16) The curren of he power supply swiching ransisor is deeced on he secondary side by an indirec mehod of curren sensing. Informaion of he collecor curren (I c ) is obained by inegraing he volage of an auxiliary winding of he ransformer during ransisor on-ime (T on ). An exernal capacior C on pin 5 is charged during T on by he curren source I sim. The curren I sim is he reflecion of he curren which flows ino pin 12. This curren is obained by connecing an exernal resisor R12 o he auxiliary ransformer winding. During ransisor on-ime his curren is relaed o he inpu volage I. During ransisor off ime (T off ) he capacior C is discharged by swich sw1. This swich is acive during he oal T off ime. In his way a sawooh volage c is formed across C. This sawooh is a measure for he collecor curren of he swiching ransisor T1. For he volage c yields: I sim T on c = C (1) lach iniializaion P () operaion MCD403 Fig.4 Lach iniializaion as a funcion of supply volage P. I T1 L n p I c n h c R12 C I I sim sw1 I sim p n h I = n p R12 (2) Where: p = reflecion facor; I p = sim = 0.2 I 12 c (2) (1) gives: p n h I c = T C n p R12 on (3) T on T off MCD404 Fig.5 Deerminaion of he peak curren I c. March

6 For T on yields: T c C n p R12 on = p n h I For he primary curren I c yields: I c I = ---- T L on Subsiuion (4) ino (5): C 1 n p I c = R12 L p n c h (4) (5) (6) Equaion (6) shows ha by limiing he volage c he collecor peak curren can be limied. The peak curren is limied by means of he clamping circui in he ransfer characer generaor (TCG); see Fig.1 sub-secion 4. The clamping level can be exernally influenced by means of a resisor on pin 7. The collecor peak curren can be influenced in several ways: Resisor R12 on pin 12 Capacior C on pin 5 Capacior on pin 7 DELAY SETTING (PIN 6) The oupu of sub-secion 11 is exended by he delay circui of sub-secion 12. The saring (reference) poin of he delay circui is he falling edge of he oupu of demagneizing comparaor (11) The delay can be deermined exernally by capacior (C delay ) on pin 6. The swich-on momen of he swiching ransisor can be deermined by capacior C delay. A minimum delay ime is required o preven ransisor T1 from swiching during demagneizaion of he ransformer because of oscillaions caused by he leakage inducance. mv Conrol par (Block III) The differenial amplifier, sub-secion 3, compares he feedback volage ( fb ) wih he reference volage ref. The oupu of he differenial amplifier is available on pin 11 o allow gain seing. The differenial amplifier is inernally compensaed for 0 db feedback sabiliy. The feedback inpu (pin 9) is also used as he inpu for he TCG (see Fig.6) wih which a curren foldback characerisic can be obained as shown in Fig.7. (3) clamp Transfer raio n h /n p Inducance L (4) Before comparing he sawooh volage c wih he conrol volage r in he pulse widh modulaor, a volage of 100 m is added o c. In his way i will be possible for r o become smaller han sim, which is imporan for a sabilized no-load operaion (see Fig.6 area 3). (1) (2) fb (5) Ton(min) MCD405 DEMAGNETIZATION INPUT (PIN 15) This inpu prevens he swiching ransisor from conducing during demagneizaion of he ransformer in order o preven he ransformer from going ino sauraion. The oupu of comparaor (11) is HIGH as soon as he volage of he ransformer winding exceeds 115 m. (1), (2), (3) = TCG. (4), (5) = diff. Fig.6 Reference volage ( mv ) as a funcion of feedback volage ( fb ). March

7 O (1), (2), (3) = TCG. (4), (5) = diff. (5) (1) (4) (2) Fig.7 Curren foldback characerisic; sabilized oupu volage ( O ) as funcion of load curren (I O ). (3) I O MCD406 The volage Ton(min) deermines he minimum on-ime of he swiching ransisor. This volage can be deermined exernally wih a resisor on pin 4. Wih his resisor he curren foldback characerisic can be influenced (see doed line in Figs 6 and 7). The minimum on-ime is of imporance for he following. Sand-by operaion Saring-up of power supply Overload and shor-circui condiions. The oupu of he differenial amplifier ( diff ), he oupu of he TCG ( TCG ) and he volage ss + Ton(min) are compared in a minimum volage clamping circui (see Fig.1 sub-secion 6). The oupu volage is equal o he lowes inpu volage. Some relevan characerisics of he conrol par are depiced in Fig.8. handbook, full pagewidh I c (max) I c mv x y TCG diff mv exernal peak-curren seing (pin 7) I c (min) ref ss + Ton(min) fb MCD407 The volage mv deermines he collecor peak curren I c of ransisor T1. The righ-hand curve is passed hrough a sar-up. When he feedback volage slowly increases from zero, he peak curren sars a I c(min) and rises along he sraigh line unil I c(max) is reached. A a slighly higher feedback volage he regulaion slope is reached, which is approximaely ref. The plaeau of he op beween he poins x and y has o be kep as small as possible. The volage diff decreases wih he decreasing load. For good no-load operaion he peak curren has o be made zero wih diff. Due o he characerisic of he TCG open- and shor-circui feedback loop will resul in low peak curren. An addiional signal on pin 13 can be supplied which is subraced from he signal mv. This inpu can be used for feed forward informaion. If no feed forward informaion is used, pin 13 should be conneced o ground. Fig.8 Characerisics of he conrol par. March

8 Pulse widh modulaor (Block I) The pulse widh modulaor compares he conrol volage r wih he sawooh volage sim. If sim > r oupu sub-secion 8 is HIGH he LED is swiched on and hen he swiching ransisor is swiched off. In his way he oupu volage is conrolled. EXAMPLE If he load decreases, O increases and herefore r decreases. This causes he LED o sar conducing premaurely, which implies ha he swiching ransisor is urned off sooner. The consequence is ha he collecor peak curren decreases and hence less energy is sored in he ransformer and O will decrease. LED conrol (Block ) If eiher oupu of sub-secion 8 or oupu of sub-secion 16 are HIGH he LED is conducive. In order o improve he sar-up behaviour of he power supply, he demagneizaion signal of sub-secion 12 will only acivae he LED driver if flip-flop (13) has previously been se. The se signal is generaed in he following hree ways. 1. Pulse widh modulaor (sub-secion 8) 2. Comparaor (18) 3. P(min) deecor Se signal (2.) and (3.) are added as exra securiy o guaranee a demagneizaion pulse in he even of he swiching ransisor no having enough base curren. In ha siuaion e.g. a sar-up, no comparaor signal, se signal (3.) is generaed by sub-secion 8. LED driver (Block I) The LED driver (pin 2) is blocked if he supply volage P is in he iniializaion phase (see Fig.4). The oupu sage is a push-pull sage, which can sink 5 ma and source 10 ma. Slow-sar circui (Block II) The slow-sar circui is acive a sar-up, over volage proecion or afer an overload (shor-circuied), and sand-by mode. The volage ss and herefore he volage mv and he peak curren I c slowly increase a sar-up. By means of sub-secion 27 he slow sar volage ss is clamped o he volage fb. If he feedback volage is reduced, e.g. as overload, he slow-sar capacior is discharged o he level of fb. In his way a slow sar-up is also guaraneed afer an overload, shor-circui siuaion or afer a sand-by mode. The circui of sub-secion 27 is no acive during an over volage proecion. When he supply volage P is below he rese-level of 5.2 (sub-secion 28) he slow-sar capacior is quickly discharged. The slow-sar inpu (pin 7) can also be used for I c(max) seing by connecing a resisor o his pin. Over volage proecion (Block III) The operaion of he over volage proecion circui is, in he even of he IC being SOPS-supplied, quie differen from when he IC is exernally supplied. OPERATION WHEN THE IC IS EXTERNALLY SUPPLIED When he volage on pin 8 exceeds 2.5 he slow-sar capacior is slowly discharged. During discharge he LED is permanenly conducing. Discharge is sopped when ss is below 115 m. Flip-flop (23) will hen be rese and he circui is ready again for a new slow-sar procedure. During an over volage sub-secion 27 is no acive so ha he oupu volage O canno influence he slow-sar discharge procedure. OPERATION WHEN IC IS SOPS-SUPPLIED (SEE FIGS 9 AND 10) When he volage on pin 8 exceeds 2.5 he slow-sar capacior is slowly discharged. During discharge of C ss he supply capacior C P is also discharged. Because he capaciors C P and C ss have almos he same value and he supply curren I P ( 15 ma) is much larger han he slow discharge curren ( 50 µa), he LED will be swiched off by means of he P(min) deecion circui (5.2 ). A ha momen he swiching ransisor will be swiched on again unil he 7.5 level is reached. During his hyseresis inerval he slow-charge capacior is quickly discharged. A he 7.5 level he LED will be swiched on again because flip-flop (23) oupu is sill HIGH. The same procedure will be repeaed several imes unil he slow-sar capacior reaches he 115 m rese level. A ha momen he slow-sar procedure is sared again. If here is sill an over volage he procedure will be repeaed. Figure 10 is a deailed exposure of Fig.11. March

9 handbook, full pagewidh I c (1) ss (1) For deail see Fig.10. MCD408 Fig.9 Over volage proecion. P () ss () 0 slow discharge delay quick discharge 0 I c Q FF23 MCD409 Fig.10 Deailed over volage proecion of Fig.9. March

10 Sand-by circui (Block IX) During sand-by operaion he volage sb is supplied from he SOPS via hyrisor TH1 (see Fig.16). In he sand-by sae, SOPS operaes in a burs mode. When he volage on pin 10 exceeds 2.5 he LED driver is permanenly acivaed. The LED driver is released again if he volage is below 2 (see Fig.11). handbook, full pagewidh sb () oupu sub-secion 25 0 I LED (ma) 5 ma 0 MCD410 Fig.11 Sand-by operaion; burs mode. March

11 Regulaion indicaor oupu (Block X) Pin 1 can be used o rese he logic circui in he T receiver a power on and off. Sub-secion 29 has an open-collecor oupu. The oupu of his block is LOW during he regulaion mode ( diff < s ; see Fig.12). handbook, full pagewidh fb 2.5 s 0 diff P 0 RIO : open-collecor oupu RIO 0 MCD411 A desired delay a power-on rese can be made exernally. Fig.12 Regulaion indicaor oupu; pin 1. March

12 LIMITING ALUES In accordance wih he Absolue Maximum Raing Sysem (IEC 134). All volages are measured wih respec o ground; posiive curren flow ino he IC; all pins no menioned in he volage lis are no allowed o be volage driven. The volage raings are valid provided oher raings are no violaed; curren raings are valid provided he power raing is no violaed. SYMBOL PARAMETER CONDITIONS MIN. MAX. UNIT olages P supply volage pin 2 conneced pin 2 open-circui n volage on pins 1, 2, 4, 7, 9 and volage on pin ,10 volage on pins 8 and volage on pin volage on pin Currens I 1 curren on pin ma I n curren on pins 2, 12 and ma I 3 curren on pin ma I 5, 6 curren on pins 5 and ma I 7 curren on pin ma I 11 curren on pin ma I 16 curren on pin ma Temperaures T amb operaing ambien emperaure C T sg sorage emperaure C Power dissipaion P o oal power dissipaion 500 mw THERMAL RESISTANCE SYMBOL PARAMETER THERMAL RESISTANCE R h j-a from juncion o ambien in free air 55 K/W March

13 CHARACTERISTICS P = 15 ; I 3 = 200 µa; T amb = 25 C; unless oherwise specified. SYMBOL PARAMETER CONDITIONS MIN. TYP. MAX. UNIT Supply P supply volage (pin 16) supply iniializaion level (hys) inernal fixed hyseresis I 16 supply curren acive LED oupu 20 ma 11 supply volage ripple rejecion see Figs 13 and m Reference volage 3 reference volage a pin Error amplifier 9 hreshold volage error ampliude I 9 inpu curren feedback inpu 0.5 µa I 11 sink curren oupu 11 = 80 m 400 µa I 11 source curren oupu 11 = µa G o open loop gain 100 db B uniy gain bandwidh 600 khz 9 / T emperaure coefficien ± K 1 5 hreshold for swiching oupu diff = 1.25 ; 4 = 2 ; 13 = 0 ; 7 > 9 ; I 2 = 2 ma Transfer characerisic generaor diff os (1) I 4 /I 3 curren raio 4 = hreshold for swiching oupu 4 = 0.5 ; 13 = 0 ; 7 > 9 ; I 2 = 2 ma PLH PHL Feed forward 5 T on(min) 9 = os 0.5 os 0.6 os fb = 20% 9 = os fb = 50% 9 = os 1.5 os 1.6 os fb = 80% 9 = os clamp 9 = os 2.6 os response ime pulse widh modulaion pin 5 o pin 2 LOW-o-HIGH response ime pulse widh modulaion pin 5 o pin 2 HIGH-o-LOW hreshold for swiching oupu ( fo ) noe ns noe 2 1 µs 4 = 0.5 ; 13 = 0 ; 7 = 9 = 3 ; I 2 = 2 ma; 11 = os 0.7 os 0.8 os I 13 inpu bias curren 13 = 0 1 µa March

14 SYMBOL PARAMETER CONDITIONS MIN. TYP. MAX. UNIT Slow-sar I 7 /I 3 charge curren raio 7 = I 7 quick discharge curren 7 = 1 20 ma 7 = 100 m 50 µa 7 clamping level I 7 = 100 µa Oupu sage hreshold for swiching oupu ( ss ) 4 = 0.5 ; 13 = 0 ; 7 = 1 ; I 2 = 2 ma; 9 = os 1.5 os 1.6 os 2(sa) sauraion volage I 2 = 2 ma 300 m I 2 source curren 2 = 2 operaing ma iniializaion phase 50 µa 2 open oupu volage HIGH I 2 = 5 ma 12 Curren simulaion I 5 /I 12 curren raio 5 = 1 ; I 12 = 0.5 ma simulaion inpu volage I 12 = 0.5 ma 1.1 5(sa) sauraion volage 15 = 6 = 0 ; I 5 = 1 ma hreshold for swiching oupu; volage difference beween pins 5 and 11; offse simulaion volage ( os ) Demagneizaion inpu demlh delay from pin 15 o pin 5 LOW-o-HIGH demhl delay from pin 15 o pin 5 HIGH-o-LOW 15 = 6 = 0 ; I 5 = 200 µa 4 = 0.5 ; 13 = 0 ; 7 = 9 = 3 ; I 2 = 2 ma; 11 = 0.5 see Fig.15; pin 6 no conneced 15 clamping level I 15 = 10 ma m 200 m m 500 ns see Fig.15 1 µs posiive 1.2 negaive 1 demagneizaion hreshold volage m C 15 inpu capaciance 10 pf I 15 inpu bias curren 15 = 60 m 0.5 µa March

15 SYMBOL PARAMETER CONDITIONS MIN. TYP. MAX. UNIT Delay seing I 6 /I 3 charge curren raio 6 = I 6 charge curren iniializaion phase 6 = 1 ; 16 = 5 2 ma 6 clamping level (sa) sauraion volage 15 = 140 m m dlh delay from pin 6 o pin 2; 6 crossing he 2.5 level; LOW-o-HIGH Noes 1. os = offse. C 6 = 470 pf; 5 = 0 ; I 2 = 2 ma; 15 see Fig.15; excluding capaciive olerances /c delay seing ( = C 6 /I) 6 = 2.5 ; I 3 = 250 µa Sand-by 2. 5 pulse = 1 ; 4 = 0.5 ; 9 = 7 = 3 ; 11 = 0.5 ; 13 = 0 ; I 2 = 2 ma. 1.2 µs 10 ns/pf 10H hreshold level HIGH (hys) hyseresis m dlh delay o oupu pin 10 o pin 2 LOW-o-HIGH dhl delay o oupu pin 10 o pin 2 HIGH-o-LOW 1 µs 1 µs I 10 inpu curren 10 = µa Over volage proecion 8 hreshold level dlh delay o oupu pin 8 o pin 2 LOW-o-HIGH dhl delay o oupu pin 8 o pin 2 HIGH-o-LOW 1 µs 1 µs 7 rese level m I 7 /I 3 slow discharge curren raio 7 = I 8 inpu curren 8 = 3 1 µa Regulaion indicaor oupu 1 sauraion volage I 1 = 1 ma 300 m I 1 leakage curren 1 = 16 1 µa March

16 P diff (pin 11) 15 2 ~ 3 MCD412 MCD413 Frequency = 50 khz. Slew rae = 0.2 µs. Fig.13 Supply volage ripple rejecion; P as a funcion of ime. Frequency = 50 khz. Slew rae = 0.2 µs. Fig.14 Supply volage ripple rejecion; diff as a funcion of ime. Table 1 Condiion of es circui used for Figs 13 and 14. PINS STATUS 1, 2, 4 o 6, 12, 13 no conneced 8 o 10, 14, 15 ground 3 R ref = 2.7 kω 7 C ss = 4.7 µf 16 P ; see Fig diff ; see Fig.14 March

17 handbook, full pagewidh 115 m ~ demagneizaion inpu (pin 15) 0 ~ % 1 peak-curren seing inpu (pin 5) 10% 0 demlh demhl MCD414 Fig.15 Timing diagram; demagneizaion delay ime. March

18 APPLICATION INFORMATION f O n s TH1 n p sab R15 A C C C delay ss P R ref n R h R12 C P Ton(min) handbook, full pagewidh (mains) 1/2 CNR50 C o A I c T1 RC Fig.16 Applicaion circui of SOPS wih sand-by faciliy. 1/2 CNR50 MCD415 I March

19 handbook, full pagewidh f O I c ns np I T on T off sorage ime and delay (SOPS) oupu sub-secion 11 oupu sub-secion 12 DEMAGNETIZATION RESET (sub-secion 13) delay c r (oupu sub-secion 7) sim comparaor (18) sim (oupu sub-secion 10) level = 1 oupu sub-secion 8 COMPARATOR SET (sub-secion 13) oupu sub-secion 13 Q oupu sub-secion 16 DEMAGNETIZATION oupu sub-secion 14 LED driver MCD416 Fig.17 Applicaion iming diagram. March

20 PACKAGE OUTLINE seaing plane min 5.1 max max 2.54 (14x) 1.4 max 0.53 max M 0.32 max MSA Dimensions in mm. Fig lead dual in-line; plasic wih inernal hea spreader; opposie ben leads (SOT38WBE). March

21 SOLDERING Plasic dual in-line packages BY DIP OR WAE The maximum permissible emperaure of he solder is 260 C; his emperaure mus no be in conac wih he join for more han 5 s. The oal conac ime of successive solder waves mus no exceed 5 s. DEFINITIONS The device may be mouned up o he seaing plane, bu he emperaure of he plasic body mus no exceed he specified sorage maximum. If he prined-circui board has been pre-heaed, forced cooling may be necessary immediaely afer soldering o keep he emperaure wihin he permissible limi. REPAIRING SOLDERED JOINTS Apply a low volage soldering iron below he seaing plane (or no more han 2 mm above i). If is emperaure is below 300 C, i mus no be in conac for more han 10 s; if beween 300 and 400 C, for no more han 5 s. Daa shee saus Objecive specificaion Produc specificaion Limiing values This daa shee conains arge or goal specificaions for produc developmen. This daa shee conains preliminary daa; supplemenary daa may be published laer. This daa shee conains final produc specificaions. Limiing values given are in accordance wih he Absolue Maximum Raing Sysem (IEC 134). Sress above one or more of he limiing values may cause permanen damage o he device. These are sress raings only and operaion of he device a hese or a any oher condiions above hose given in he Characerisics secions of he specificaion is no implied. Exposure o limiing values for exended periods may affec device reliabiliy. Applicaion informaion Where applicaion informaion is given, i is advisory and does no form par of he specificaion. LIFE SUPPORT APPLICATIONS These producs are no designed for use in life suppor appliances, devices, or sysems where malfuncion of hese producs can reasonably be expeced o resul in personal injury. Philips cusomers using or selling hese producs for use in such applicaions do so a heir own risk and agree o fully indemnify Philips for any damages resuling from such improper use or sale. March

DATA SHEET. 1N914; 1N916 High-speed diodes DISCRETE SEMICONDUCTORS Sep 03

DATA SHEET. 1N914; 1N916 High-speed diodes DISCRETE SEMICONDUCTORS Sep 03 DISCRETE SEMICONDUCTORS DATA SHEET M3D176 Supersedes daa of April 1996 File under Discree Semiconducors, SC01 1996 Sep 03 FEATURES Hermeically sealed leaded glass SOD27 (DO-35) package High swiching speed: