Ultra-Fast ECL-Output Comparator with Latch Enable MAX9685. Features

Transcription

1 19-239; Rv 1; 7/93 Ultra-Fast -Output omparator with atch nabl Gnral scription Th 965 is an ultra-fast comparator manufacturd with a high-frquncy bipolar procss (ft = 6GHz) capabl of vry short propagation dlays. This dsign maintai th xcllnt matching charactristics normally found only in slowr comparators. Th dvic is pin-compatibl with th 965 and m665, but xcds thir charactristics. Th 965 has diffrntial inputs and complmntary outputs that ar fully compatibl with -logic lvls. Output currnt lvls ar capabl of driving 50Ω trminatd tramission li. Th ultra-fast opration maks signal procssing possibl at frquncis in xcss of 600MHz. latch-nabl () function is providd to allow th comparator to b usd in a sampl-hold mod. Whn is high, th comparator functio normally. Whn is drivn low, th outputs ar forcd to an unambiguous -logic stat, dpndnt on th input conditio at th tim of th latch input traition. If th latch-nabl function is not usd, th pin must b connctd to ground. pplicatio High-Spd / onvrtrs High-Spd in Rcivrs ak tctors Thrshold tctors High-Spd Triggrs Faturs 1.3 ropagation lay 0.5 atch Stup Tim +5V, -5.2V owr Supplis in-ompatibl with 965, m665 vailabl in ommrcial, xtndd-industrial, and Military Tmpratur Rangs vailabl in Narrow SO ackag Ordring Information RT TM. RNG IN-KG* to lastic I 965S 0 to Narrow SO 965J 0 to RI 965TW 0 to TO / 0 to +70 ic** to lastic I 965S -40 to Narrow SO 965MJ -55 to RI 965MTW -55 to TO-100 * ontact factory for availability of 20-pin. ** ontact factory for dic spcificatio. 965 in onfiguratio TO VIW IN+ V+ 1 2 GN GN2 OUT GN1 V+ IN+ IN GN2 15 N.. 14 N.. 13 N.. IN- 3 7 OUT N OUT 11 OUT 4 5 V- 6 N.. N.. V N.. 9 N.. TO-100 I/SO Maxim Intgratd roducts 1 all toll fr for fr sampls or litratur.

2 Ultra-Fast -Output omparator with atch nabl 965 SOUT IMUM RTINGS Supply Voltags...±6V Output Short-ircuit uration...indfinit Input Voltags...±5V iffrntial Input Voltags...7.0V Output urrnt...30m ontinuous owr issipation (T = +70 ) lastic I (drat 10.53mW/ abov +70 )...42mW Narrow SO (drat.70mw/ abov +70 )...696mW RI (drat 10.00mW/ abov +70 )...00mW TO-100 (drat 6.67mW/ abov +70 )...533mW Oprating Tmpratur Rangs to to M to +125 Storag Tmpratur Rang to +150 ad Tmpratur (soldring, 10sc) Strsss byond thos listd undr bsolut Maximum Ratings may caus prmannt damag to th dvic. Ths ar strss ratings only, and functional opration of th dvic at ths or any othr conditio byond thos indicatd in th oprational sctio of th spcificatio is not implid. xposur to absolut maximum rating conditio for xtndd priods may affct dvic rliability. TRI HRTRISTIS (V+ = +5V, V- = -5.2V, R = 50Ω, V T = -2V, T = +25, unlss othrwis notd.) RMTR SYMO ONITIONS 965/ 965M TY TY UNITS Input Offst Voltag V OS R S =100Ω T = T = T to T mv Tmpratur officint V OS / T µv/ Input Offst urrnt I OS T = T = T to T 12 µ Input ias urrnt I T = T = T to T µ Input Voltag Rang V M (Not 1) V ommon-mod Rjction Ratio MRR 0 0 d owr-supply Rjction Ratio SRR d Input Rsistanc R IN (Not 1) kω Input apacitanc IN 3 3 pf T = T , 965M T = T ogic Output High T = V Voltag OH T = T V 965 T = T T = T = T , 965M T = T ogic Output ow T = V Voltag O T = T V 965 T = T T = ositiv Supply urrnt I T = T = T to T m Ngativ Supply T = I urrnt T = T to T m 2

3 Ultra-Fast -Output omparator with atch nabl SWITHING HRTRISTIS (V+ = 5V, V- = -5.2V, R = 50Ω, V T = -2V, T = +25, unlss othrwis notd.) 965/ 965M RMTR SYMO ONITIONS UNITS TY TY T = Input to Output High t T = 0 to (Nots 1, 2) pd+ T = -55 to Input to Output ow (Nots 1, 2) T = t pd- T = 0 to T = -55 to atch-nabl to Output High (Nots 1, 2) t pd+() T = T = 0 to T = -55 to atch-nabl to Output High (Nots 1, 2) t pd-() T = T = 0 to T = -55 to atch-nabl uls Width (Not 2) t pw() Minimum Stup Tim t s Minimum Hold Tim t h Not 1: Not tstd, guarantd by dsign. Not 2: V IN = 100mV, V O = 10mV pplicatio Information ayout caus of th 965 s larg gain-bandwidth charactristic, spcial prcautio nd to b takn if its high-spd capabilitis ar to b usd. board with a ground plan is mandatory. Mount all dcoupling capacitors as clos to th powr-supply pi as possibl, and procss th outputs in microstrip fashion, coistnt with th load trmination of 50Ω to 120Ω. For low-impdanc applicatio, microstrip layout at th input may also b hlpful. ay clos attntion to th bandwidth of th dcoupling and trminating componnts. hip componnts can b usd to minimiz lad inductanc. n unusd pin must b connctd to ground. Input Slw-Rat Rquirmnts s with all high-spd comparators, th high gainbandwidth product of ths dvics crats oscillation problms whn th input travrss through th linar rgion. For clan switching without oscillation or stps in th output wavform, th input must mt crtain minimum slw-rat rquirmnts. Th tndncy of th part to oscillat is a function of th layout and sourc impdanc of th circuit mployd. oor layout and largr sourc impdanc will incras th minimum slw-rat rquirmnt. Figur 1 shows a high-spd rcivr application with 50Ω input and output trmination. With this configuration, in which a ground plan and microstrip board wr usd, th minimum slw rat for clan output switching is 1.6V/µs. Sin-wav inputs imply a minimum signal siz of 360mV RMS at 500kHz and 90mVRMS at 4MHz. RMS = Slw Rat 2 2nf In many applicatio, th addition of rgnrativ fdback will assist th input signal through th linar rgion, which will lowr th minimum slw-rat rquirmnt coidrably. For xampl, with th addition of positiv fdback componnts R f = 1kΩ and f = 10pF, th minimum slw-rat rquirmnt can b rducd by a factor of four. 3

4 Ultra-Fast -Output omparator with atch nabl 965 V IN 50Ω 50Ω INUT INUT 20mV/div OUTUT 500mV/div 2/div -0V 50Ω R f f 50Ω -2V OUTUT -0.9V -1.7V Figur 1. Rgnrativ Fdback. High-spd rcivr with 50Ω input and output trmination. Figur 2. s a high-spd rcivr, th 965 is capabl of procssing signals in xcss of 600MHz. Figur 2 is a 100MHz xampl with an input signal lvl of 14mV RMS. Th timing diagram (Figur 3) illustrats th sris of vnts that complt th compar function, undr worst-cas conditio. Th top lin of th diagram illustrats two latch-nabl pulss. ach puls is high for th compar function and low for th latch function. Th first puls dmotrats th compar function; part of th input action taks plac during th compar mod. Th scond puls dmotrats a compar-function intrval during which thr is no chang in th input. Th lading dg of th input signal (illustratd as a larg-amplitud, small-ovrdriv puls) switchs th comparator aftr tim intrval t pd. Output and traistors ar similar in timing. Th input signal must occur at tim ts bfor th latch falling dg, and it must b maintaind for tim th aftr th dg to b acquird. ftr th, th output is no longr affctd by th input status until th latch is again strobd. minimum latch puls width of t pw() is ndd for th strob opration, and th output traitio occur aftr a tim t pd(). VOS VIN VO tpd+ finition of Trms Input Offst Voltag Th voltag rquird btwn th input trminals to obtain 0V diffrntial at th output. Input Voltag uls mplitud Input Voltag Ovrdriv Input to Output High lay Th propagation dlay masurd from th tim th input signal crosss th input offst voltag to th 50% point of an output low-to-high traition. tpdtpd+() tpd-() tpw() ts th Input to Output ow lay Th propagation dlay masurd from th tim th input signal crosss th input offst voltag to th 50% point of an output high-to-low traition. atch-nabl to Output High lay Th propagation dlay masurd from th 50% point of th latch-nabl signal low-to-high traition to th 50% point of an output low-tohigh traition. atch-nabl to Output ow lay Th propagation dlay masurd from th 50% point of th latch-nabl signal low-to-high traition to th 50% point of an output highto-low traition. Minimum atch-nabl uls Width Th minimum tim th latch-nabl signal must b high to acquir and hold an input signal. Minimum Stup Tim Th minimum tim bfor th ngativ traition of th latchnabl puls that an input signal must b prsnt to b acquird and hld at th outputs. Minimum Hold Tim Th minimum tim aftr th ngativ traition of th latch-nabl signal that an input signal must rmain unchangd to b acquird and hld at th output. 4

5 Ultra-Fast -Output omparator with atch nabl TH N IFFRNTI INUT VOTG TH V IN OMR t s th t pw () 50% V OS 965 V O t pd t pd () 50% 50% Figur 3. Timing iagram 5

6 965 Ultra-Fast -Output omparator with atch nabl 6 ackag Information IM MIIMTRS lastic I STI U-IN-IN KG (0.300 in.) IM KG. N MIIMTRS INS IM 1 H MIIMTRS Narrow SO SM-OUTIN KG (0.150 in.) IM MIIMTRS INS H mm 0.004in.

7 965 Ultra-Fast -Output omparator with atch nabl 7 ackag Information (continud) IM S S S1 RI RMI U-IN-IN KG (0.300 in.) S 1 1 INS IM MIIMTRS MIIMTRS φ1 IM φb φb1 φ φ1 φ2 1 F k k1 1 2 α β MIIMTRS IN TO-100 MT N KG 5.4 S S φ 1 β α 1 φ2 k k1 F φb1 φb S & STING N S S 36 S 36 S 36 S 36 S

8 Ultra-Fast -Output omparator with atch nabl 965 Maxim cannot assum rspoibility for us of any circuitry othr than circuitry ntirly mbodid in a Maxim product. No circuit patnt lics ar implid. Maxim rsrvs th right to chang th circuitry and spcificatio without notic at any tim. Maxim Intgratd roducts, 120 San Gabril riv, Sunnyval, 9406 (40) Maxim Intgratd roducts rintd US is a rgistrd tradmark of Maxim Intgratd roducts.