Data Sheet. HSMS-2700, 2702, 270B, 270C High Performance Schottky Diode for Transient Suppression. Features. Description.

Transcription

1 HSMS-2700, 2702, 270B, 270 High Prformanc Schottky iod for Transint Supprssion ata Sht scription Th HSMS-2700 sris of Schottky diods, commonly rfrrd to as clipping /clamping diods, ar optimal for circuit and wavshap prsrvation applications with high spd switching. Ultra-low sris rsistanc, R S, maks thm idal for protcting snsitiv circuit lmnts against highr currnt transints carrid on data lins. With picoscond switching, th HSMS-270x can rspond to nois spiks with ris tims as fast as ns. Low capacitanc minimizs wavshap loss that causs signal dgradation. Faturs Ultra-low Sris Rsistanc for Highr urrnt Handling Picoscond Switching Low apacitanc Lad-fr Option Availabl Applications RF and computr dsigns that rquir circuit protction, high-spd switching, and voltag clamping. HSMS-270x lctrical Spcifications, T A = +25 [] Part Numbr HSMS- Packag Marking od [2] Lad od onfiguration Packag J0 0 Singl SOT-2-270B B SOT-2 (-lad S-70) SOT J2 Sris SOT-2 (-lad S-70) Maximum Forward Voltag V F (mv) Minimum Brakdown Voltag V BR (V) Typical apacitanc T (pf) Typical Sris Rsistanc R S (Ω) Maximum ff. arrir Liftim τ (ps) 550 [] 5 [4] 6.7 [5] 0.65 [6] Nots:. T A = +25, whr T A is dfind to b th tmpratur at th packag pins whr contact is mad to th circuit board. 2. Packag marking cod is lasr markd.. I F = ma; % tstd 4. I R = µa; % tstd 5. V F = 0; f = MHz 6. Masurd with Karkaur mthod at 20 ma; guarantd by dsign. Packag Lad od Idntification (Top Viw) SINGL SRIS 0, B 2 2, 2

2 Absolut Maximum Ratings, T A = 25º Symbol Paramtr Unit Absolut Maximum [] HSMS-2700/-2702 I F Forward urrnt ma I F-pak Pak Surg urrnt (µs puls) A.0.0 P T Total Powr issipation mw P INV Pak Invrs Voltag V 5 5 T J Junction Tmpratur HSMS-270B/-270 T STG Storag Tmpratur -65 to to 50 θ J Thrmal Rsistanc, junction to lad /W Not:. Opration in xcss of any on of ths conditions may rsult in prmannt damag to th dvic. Linar and Non-linar SPI Modl SPI Paramtrs 2 nh R S 0.08 pf SPI modl Paramtr Unit Valu BV V 25 JO pf 6.7 G V 0.55 IBV A 0-4 IS A.4-7 N.04 RS Ω 0.65 PB V 0.6 PT 2 M 0.5 2

3 Typical Prformanc I F FORWAR URRNT (ma) T A = +75 T A = +25 T 0.0 A = V F FORWAR VOLTAG (V) Figur. Forward urrnt vs. Forward Voltag at Tmpratur for HSMS-2700 and HSMS I F FORWAR URRNT (ma) T A = +75 T A = +25 T 0.0 A = V F FORWAR VOLTAG (V) Figur 2. Forward urrnt vs. Forward Voltag at Tmpratur for HSMS-270B and HSMS-270. T J JUNTION TMPRATUR ( ) 60 Max. saf junction tmp T A = +75 T A = +25 T A = I F FORWAR URRNT (ma) Figur. Junction Tmpratur vs. Forward urrnt as a Function of Hat Sink Tmpratur for th HSMS-2700 and HSMS Not: ata is calculatd from SPI paramtrs. T J JUNTION TMPRATUR ( ) 60 Max. saf junction tmp T A = +75 T A = +25 T A = I F FORWAR URRNT (ma) Figur 4. Junction Tmpratur vs. urrnt as a Function of Hat Sink Tmpratur for HSMS-270B and HSMS-270. Not: ata is calculatd from SPI paramtrs. T TOTAL APAITAN (pf) V F RVRS VOLTAG (V) Figur 5. Total apacitanc vs. Rvrs Voltag.

4 Packag imnsions Outlin SOT-2 2 vic Orintation For Outlins SOT-2/2 RL XXX L USR F IRTION OVR TAP ARRIR TAP A B Nots: XXX-packag marking rawings ar not to scal A SYMBOL A A B 2 L IMNSIONS (mm) MIN MAX mm TOP VIW 4 mm AB AB AB AB Not: "AB" rprsnts packag marking cod. "" rprsnts dat cod. N VI W Tap imnsions and Product Orintation For Outlin SOT-2 Rcommndd PB Pad Layout For Avago s SOT-2 Products P P 2 P F W t MAX Ko 8 MAX.5 MAX A 0 B 0 imnsions in inchs mm AVITY PRFORATION SRIPTION SYMBOL SIZ (mm) SIZ (INHS) LNGTH WITH PTH PITH BOTTOM HOL IAMTR IAMTR PITH POSITION A 0 B 0 K 0 P P 0.5 ± ± ± ± ± ± ± ± ± ± ± ± ± ARRIR TAP WITH THIKNSS W t ± ± ISTAN BTWN NTRLIN AVITY TO PRFORATION (WITH IRTION) AVITY TO PRFORATION (LNGTH IRTION) F P 2.50 ± ± ± ±

5 Packag imnsions Outlin SOT-2 (S-70 Lad) Rcommndd PB Pad Layout For Avago s S70 L /SOT-2 Products XXX L 0.09 B A Nots: XXX-packag marking rawings ar not to scal A SYMBOL A A B L IMNSIONS (mm) MIN. MAX typical.0 typical typical imnsions in inchs Tap imnsions and Product Orintation For Outlin SOT-2 (S-70 Lad) P P 2 P 0 F W t (ARRIR TAP THIKNSS) T t (OVR TAP THIKNSS) 8 MAX. K 0 8 MAX. A 0 B 0 AVITY PRFORATION ARRIR TAP OVR TAP ISTAN SRIPTION SYMBOL SIZ (mm) SIZ (INHS) LNGTH WITH PTH PITH BOTTOM HOL IAMTR IAMTR PITH POSITION WITH THIKNSS WITH TAP THIKNSS AVITY TO PRFORATION (WITH IRTION) AVITY TO PRFORATION (LNGTH IRTION) A 0 B 0 K 0 P P ± ± ± ± ± ± ± 0.0 W 8.00 ± 0.0 t ± ± 0.0 T t ± 0.00 F P 2.50 ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

6 Applications Information Schottky iod Fundamntals Th HSMS-270x sris of clipping/clamping diods ar Schottky dvics. A Schottky dvic is a rctifying, mtal-smiconductor contact formd btwn a mtal and an n dopd or a p-dopd smiconductor. Whn a mtal-smiconductor junction is formd, fr lctrons flow across th junction from th smiconductor and fill th fr-nrgy stats in th mtal. This flow of lctrons crats a dpltion or potntial across th junction. Th diffrnc in nrgy lvls btwn smiconductor and mtal is calld a Schottky barrir. P-dopd, Schottky-barrir diods xcl at applications rquiring ultra low turn-on voltag (such as zro-biasd RF dtctors). But thir vry low, brakdown-voltag and high sris-rsistanc mak thm unsuitabl for th clipping and clamping applications involving high forward currnts and high rvrs voltags. Thrfor, this discussion will focus ntirly on n dopd Schottky diods. Undr a forward bias (mtal connctd to positiv in an n dopd Schottky), or forward voltag, V F, thr ar many lctrons with nough thrmal nrgy to cross th barrir potntial into th mtal. Onc th applid bias xcds th built-in potntial of th junction, th forward currnt, I F, will incras rapidly as V F incrass. Whn th Schottky diod is rvrs biasd, th potntial barrir for lctrons bcoms larg; hnc, thr is a small probability that an lctron will hav sufficint thrmal nrgy to cross th junction. Th rvrs lakag currnt will b in th nanoampr to microampr rang, dpnding upon th diod typ, th rvrs voltag, and th tmpratur. In contrast to a convntional p-n junction, currnt in th Schottky diod is carrid only by majority carrirs (lctrons). Bcaus no minority-carrir (hol) charg storag ffcts ar prsnt, Schottky diods hav carrir liftims of lss than ps. This xtrmly fast switching tim maks th Schottky diod an idal rctifir at frquncis of 50 GHz and highr. Anothr significant diffrnc btwn Schottky and p-n diods is th forward voltag drop. Schottky diods hav a thrshold of typically 0. V in comparison to that of 0.6 V in p-n junction diods. S Figur 6. Through th carful manipulation of th diamtr of th Schottky contact and th choic of mtal dpositd on th n-dopd silicon, th important charactristics of th diod (junction capacitanc, J ; parasitic sris rsistanc, R S ; brakdown voltag, V BR ; and forward voltag, V F,) can b optimizd for spcific applications. Th HSMS- 270x sris and HBAT 540x sris of diods ar a cas in point. Both diods hav similar barrir hights; and this is indicatd by corrsponding valus of saturation currnt, I S. Yt, diffrnt contact diamtrs and pitaxial-layr thicknss rsult in vry diffrnt valus of J and R S. This is sn by comparing thir SPI paramtrs in Tabl. Tabl. HSMS-270x and HBAT 540x SPI Paramtrs. Paramtr HSMS- 270x HBAT- 540x BV 25 V 40 V J0 6.7 pf.0 pf G 0.55 V 0.55 V IBV 0-4 A 0-4 A IS.4-7 A.0-7 A N.04.0 RS 0.65 Ω 2.4 Ω PB 0.6 V 0.6 V PT 2 2 M At low valus of I F ma, th forward voltags of th two diods ar narly idntical. Howvr, as currnt riss abov 0 ma, th lowr sris rsistanc of th HSMS- 270x allows for a much lowr forward voltag. This givs th HSMS-270x a much highr currnt handling capability. Th trad-off is a highr valu of junction capacitanc. Th forward voltag and currnt plots illustrat th diffrncs in ths two Schottky diods, as shown in Figur HSMS-270x P N APAITAN URRNT 0.6V + BIAS VOLTAG PN JUNTION Figur 6. MTAL N URRNT APAITAN 0.V + BIAS VOLTAG SHOTTKY JUNTION I F FORWAR URRNT (ma) 0..0 HBAT-540x V F FORWAR VOLTAG (V) Figur 7. Forward urrnt vs. Forward Voltag at 25. 6

7 Bcaus th automatic, pick-and-plac quipmnt usd to assmbl ths products slcts dic from adjacnt sits on th wafr, th two diods which go into th HSMS-2702 or HSMS-270 (sris pair) ar closly matchd without th addd xpns of tsting and binning. urrnt Handling in lipping/lamping ircuits Th purpos of a clipping/clamping diod is to handl high currnts, protcting dlicat circuits downstram of th diod. urrnt handling capacity is dtrmind by two sts of charactristics, thos of th chip or dvic itslf and thos of th packag into which it is mountd. noisy data-spiks long cross-sit cabl V F FORWAR VOLTAG (V) pull-down (or pull-up) currnt limiting R s = 7.7 Ω R s =.0 Ω I F FORWAR URRNT (ma) Figur 9. omparison of Two iods Figur 9. omparison of Two iods. 0V Figur 8. Two Schottky iods Ar Usd for lipping/lamping in a ircuit. onsidr th circuit shown in Figur 8, in which two Schottky diods ar usd to protct a circuit from nois spiks on a stram of digital data. Th ability of th diods to limit th voltag spiks is rlatd to thir ability to sink th associatd currnt spiks. Th importanc of currnt handling capacity is shown in Figur 9, whr th forward voltag gnratd by a forward currnt is compard in two diods. Vs voltag limitd to Vs + Vd 0V Vd taind at a low limit vn at high valus of currnt. Maximum rliability is obtaind in a Schottky diod whn th stady stat junction tmpratur is maintaind at or blow 50, although brif xcursions to highr junction tmpraturs can b tolratd with no significant impact upon man-tim-to-failur, MTTF. In ordr to comput th junction tmpratur, quations () and () blow must b simultanously solvd. 600 (V F I F R S ) ntj I F = I S () I S = I 0 T J n 4060 T J 298 (2) T J = V F I F θ J + T A () Th first is a convntional Schottky diod of th typ gnrally usd in RF circuits, with an R S of 7.7 Ω. Th scond is a Schottky diod of idntical charactristics, sav th R S of.0 Ω. For th convntional diod, th rlativly high valu of R S causs th voltag across th diod s trminals to ris as currnt incrass. Th powr dissipatd in th diod hats th junction, causing R S to climb, giving ris to a runaway thrmal condition. In th scond diod with low R S, such hating dos not tak plac and th voltag across th diod trminals is mainwhr: I F = forward currnt I S = saturation currnt V F = forward voltag R S = sris rsistanc T J = junction tmpratur I O = saturation currnt at 25 n = diod idality factor θ J = thrmal rsistanc from junction to cas (diod lad) = θ packag + θ chip T A = ambint (diod lad) tmpratur quation () dscribs th forward V-I curv of a Schottky diod. quation (2) provids th valu for th diod s saturation currnt, which valu is pluggd into (). quation () givs th valu of junction tmpratur as a function of powr dissipatd in th diod and ambint (lad) tmpratur. Th ky factors in ths quations ar: R S, th sris rsistanc of th diod whr hat is gnratd undr high currnt conditions; θ chip, th chip thrmal rsistanc of th Schottky di; and θ packag, or th packag thrmal rsistanc. R S for th HSMS-270x family of diods is typically 0.7 Ω and is th lowst of any Schottky diod availabl from Avago. hip thrmal rsistanc is typically 40 /W; th thrmal rsistanc of th iron-alloy-ladfram, SOT-2 packag is typically 460 /W; and th thrmal rsistanc of th coppr-ladfram, SOT-2 packag is typically 0 /W. Th impact of packag thrmal rsistanc on th currnt handling capability of ths diods can b sn in Figurs and 4. Hr th computd valus of junction tmpratur vs. forward currnt ar shown 7

8 for thr valus of ambint tmpratur. Th SOT-2 products, with thir coppr ladframs, can safly handl almost twic th currnt of th largr SOT-2 diods. Not that th trm ambint tmpratur rfrs to th tmpratur of th diod s lads, not th air around th circuit board. It can b sn that th HSMS-270B and HSMS 270 products in th SOT 2 packag will safly withstand a stady-stat forward currnt of 550 ma whn th diod s trminals ar maintaind at 75. For pulsd currnts and transint currnt spiks of lss than on microscond in duration, th junction dos not hav tim to rach thrmal stady stat. Morovr, th diod junction may b takn to tmpraturs highr than 50 for short tim-priods without impacting dvic MTTF. Bcaus of ths factors, highr currnts can b safly handld. Th HSMS-270x family has th highst currnt handling capability of any Avago diod. Part Numbr Ordring Information Part Numbr No. of vics ontainr HSMS-2700-BLKG HSMS-2700-TRG HSMS-2700-TR2G HSMS-2702-BLKG HSMS-2702-TRG HSMS-2702-TR2G HSMS-270B-BLKG HSMS-270B-TRG HSMS-270B-TR2G HSMS-270-BLKG HSMS-270-TRG HSMS-270-TR2G,000 0,000,000 0,000,000 0,000,000 0,000 Antistatic Bag 7" Rl " Rl Antistatic Bag 7" Rl " Rl Antistatic Bag 7" Rl " Rl Antistatic Bag 7" Rl " Rl For product information and a complt list of distributors, plas go to our wb sit: Avago, Avago Tchnologis, and th A logo ar tradmarks of Avago Tchnologis Limitd in th Unitd Stats and othr countris. ata subjct to chang. opyright Avago Tchnologis Limitd. All rights rsrvd. Obsolts N N - Jun 2, 2008