vitesse semiconductor corporation preliminary data sheet vsc7926 sdh/sonet 2.5gb/s laser diode driver g52188-0, rev 3.0 page 1 04/05/01 ? vitesse semiconductor corporation ? 741 calle plano camarillo, ca 93012 tel: (800) vitesse fax: (805) 987-5896 email: prodinfo@vitesse.com internet: www.vitesse.com features general description the vsc7926 is a single 5v supply, 2.5gb/s laser diode driver with direct access to the laser modulation and bias fets. laser bias and modulation currents are set by external components allowing precision monitor- ing and setting of the current levels. data density outputs are provided to allow the user to adjust the laser bias in high unbalanced data applications. clock and data inputs are differentially terminated to 50 ? . applications ? sdh/sonet @ 622mb/s, 1.244gb/s, 2.488gb/s full speed fibre channel (1.062gb/s) vsc7926 block diagram rise times of less than 100ps high-speed operation (up to 2.5gb/s nrz data) differential inputs single supply direct access to modulation and bias fets data density monitors on-chip reclocking register din dinterm* 50 ? mk nmk ibias niout iout mip vip vib mib dq dcc ** **on die components i mod i bias 50 ? ** ndin clk 50 ? ** 50 ? ** nclk clkterm* *terminated to off-chip capacitor dcc
vitesse semiconductor corporation preliminary data sheet vsc7926 sdh/sonet 2.5gbits/sec laser diode driver page 2 g52188-0, rev 3.0 04/05/01 ? vitesse semiconductor corporation 741 calle plano camarillo, ca 93012 tel: (800) vitesse fax: (805) 987-5896 email: prodinfo@vitesse.com internet: www.vitesse.com table 1: signal pin reference table 2: absolute maximum ratings table 3: high speed inputs and ecl outputs signal type level # pins description din, ndin in 2 data input and data reference dinterm ref dc 1 data termination clkterm ref dc 1 clock termination mk, nmk out ecl 2 data density differential outputs niout out 1 laser modulation current output (complementary) iout out 1 laser modulation current output (to laser cathode) vss pwr pwr 3 negative voltage rail gnd pwr pwr 5 positive voltage rail vip in dc 1 modulation gate node mip in dc 1 modulation source node vib in dc 1 bias gate node mib in dc 1 bias source node ibias out dc 1 laser bias output (to laser cathode) clk, nclk in 2 clock input and clock reference dcc in dc 1 duty cycle control, leave floating total pins 24 symbol rating limit v ss negative power supply voltage v cc to -6.0v t j maximum junction temperature -55 c to + 125 c t stg storage temperature -65 c to +150 c symbol parameter min max units conditions v in differential input voltage swing 500 1000 mv v cm differential input common mode range -2.3 -1.3 v v ss = -5.2v v oh ecl output high voltage -1200 mv 50 ? to -2.0v v ol ecl output low voltage -1600 mv 50 ? to -2.0v
vitesse semiconductor corporation preliminary data sheet vsc7926 sdh/sonet 2.5gb/s laser diode driver g52188-0, rev 3.0 page 3 04/05/01 ? vitesse semiconductor corporation 741 calle plano camarillo, ca 93012 tel: (800) vitesse fax: (805) 987-5896 email: prodinfo@vitesse.com internet: www.vitesse.com table 4: recommended operating conditions notes: (1) lower limit of specification is ambient temperature and upper limit is case temperature. (2) see ?calculation of the maximum case temperature? section in this data sheet for detailed maximum temperature calculations. table 5: power dissipation table 6: laser driver dc electrical specifications table 7: laser driver ac electrical specifications table 8: package thermal specifications symbol parameter min typ max units conditions gnd positive voltage rail - 0 - v vss negative voltage rail -5.5 -5.2 -4.9 v tc l operational temperature (1) -40 - 85 (2) c power dissipation = 1.25w t j junction temperature - - 125 c symbol parameter min typ max units conditions i vss power supply current (vss) - - 220 ma v ss = -5.5, i mod = i bias = 0ma p d total power dissipation - - 1210 mw v ss = -5.5, i mod = i bias = 0ma, r load = 25 ? to gnd p dmax maximum power dissipation - - 1815 mw v ss = -5.5, i mod = 60ma, i bias = 50ma, i out = 0v symbol parameter min typ max units conditions i bias programmable laser bias current 2 - 50 ma i mod programmable modulation current 2 - 60 ma v ib laser bias control voltage - - v ss + 2.1 vi bias = 50ma v ip laser modulation control voltage - - v ss + 2.1 vi mod = 60ma v ocm output voltage compliance gnd -2.5v --vv ss = -5.2v symbol parameter min typ max units conditions t r t f output rise and fall times - - 100 ps 25 ? load, 20%-80%, 15ma < i mod < 60 ma, i bias = 40ma t su setup data to clock setup time - 50 - ps t h hold time - 50 - ps symbol parameter min typ max units conditions jcc thermal resistance from junction-to-case - 25 - c/w ceramic package
vitesse semiconductor corporation preliminary data sheet vsc7926 sdh/sonet 2.5gbits/sec laser diode driver page 4 g52188-0, rev 3.0 04/05/01 ? vitesse semiconductor corporation 741 calle plano camarillo, ca 93012 tel: (800) vitesse fax: (805) 987-5896 email: prodinfo@vitesse.com internet: www.vitesse.com calculation of the maximum case temperature the vsc7926 is designed to operate with a maximum junction temperature of 125 c. the rise from the case to junction is determined by the power dissipation of the device. the power dissipation is determined by the v ss current plus the operating i mod and i bias currents. the power of the chip is determined by the following formula: p d = (- v ss * i ss ) + (( v iout ? v ss ) * i mod ) + (( v ibias ? v ss ) * i bias ) for example with: v ss =-5.2v i mod =40ma i bias =20ma v ibias =-2.0v v iout =-2.0v p d = (-5.2 * 220ma) + ((5.2 - 2.0) * 40ma) + ((5.2 - - 2.0) * 20ma) p d = 1144mw + 128mw + 64mw = 1.336w the thermal rise from junction to case is jc * p d . for the ceramic package, jcc = 25 c/w. thus the ther- mal rise is: 25 c/w * 1.336w = 33.4 c the maximum case temperature is: 125 c ? 33.4 c = 91.6 c the absolute maximum power dissipation of the device is at: v ss =-5.5v i mod =60ma i bias =50ma v ibias =0v v iout =0v p d = (5.5 * 220ma) + (5.5 * 60ma) + (5.5ma * 50ma) p d = 1.815w this will net a maximum junction to case thermal rise of: 1.815w * 25 c/w = 45.4 c this situation will allow maximum case temperature of: 125 c ? 45.4 c = 79.6 c
vitesse semiconductor corporation preliminary data sheet vsc7926 sdh/sonet 2.5gb/s laser diode driver g52188-0, rev 3.0 page 5 04/05/01 ? vitesse semiconductor corporation 741 calle plano camarillo, ca 93012 tel: (800) vitesse fax: (805) 987-5896 email: prodinfo@vitesse.com internet: www.vitesse.com figure 1: control signals vip and vib figure 2: simplified output structure 50 ma 60 ma i (mib) i (mip) vip vib 2.1v 2.1v typical bias current v.s. bias voltage typical modulation current v.s. modulation voltage x x x x x x niout iout x ibias output diff pair vib mib mip vip i mod i bias
vitesse semiconductor corporation preliminary data sheet vsc7926 sdh/sonet 2.5gbits/sec laser diode driver page 6 g52188-0, rev 3.0 04/05/01 ? vitesse semiconductor corporation 741 calle plano camarillo, ca 93012 tel: (800) vitesse fax: (805) 987-5896 email: prodinfo@vitesse.com internet: www.vitesse.com figure 3: pad assignments for vsc7926 die pad 25 pad 24 pad 23 pad 22 pad 21 pad 20 pad 19 pad 18 vib gnd0 out out gnd0 gnd0 nout ibias pad 1 pad 34 pad 33 pad 32 pad 31 pad 30 pad 29 pad 28 pad 27 pad 26 dcc vss vss vss vss vip mip mip mib pad 2 pad 3 pad 4 pad 5 pad 6 pad 7 pad 8 ndin dint din dint clockt clock clockt nclock pad 9 pad 10 pad 11 pad 12 pad 13 pad 14 pad 15 pad 16 pad 17 vss vss gnd gnd gnd gnd gnd nmark mark 120 m 120 150 m 30 m 1720 m 1620 m 1720 m 1620 m 50 m 50 m 50 m 50 m die size: 1620m x 1620m actual die size: 1720mx1720m (after the die are cut up) pad size: 120m x 120m pad pitch: 150m space between pads:30m
vitesse semiconductor corporation preliminary data sheet vsc7926 sdh/sonet 2.5gb/s laser diode driver g52188-0, rev 3.0 page 7 04/05/01 ? vitesse semiconductor corporation 741 calle plano camarillo, ca 93012 tel: (800) vitesse fax: (805) 987-5896 email: prodinfo@vitesse.com internet: www.vitesse.com pin diagram for 24-pin ceramic package 1 2 3 4 5 6 78910 11 12 13 14 15 16 17 18 24 23 22 21 20 19 ndin din dinterm clkterm clk nclk vib gnd iout gnd niout ibias vss gnd gnd gnd mk mk dcc vss vss vip mip mib note: package lid and bottom heat spreader are electrically connected to gnd within the package.
vitesse semiconductor corporation preliminary data sheet vsc7926 sdh/sonet 2.5gbits/sec laser diode driver page 8 g52188-0, rev 3.0 04/05/01 ? vitesse semiconductor corporation 741 calle plano camarillo, ca 93012 tel: (800) vitesse fax: (805) 987-5896 email: prodinfo@vitesse.com internet: www.vitesse.com package information - 24-pin ceramic package (formed leads) top view side view notes: drawing not to scale. package #: 101-300-7, issue #:1 1 2 3 4 5 6 78910 11 12 13 14 15 16 17 18 24 23 22 21 20 19 index a e a d i c g f h j b key mm in a 9.5 0.374 b 7.7 0.303 c 2.0 0.079 d1.27 0.050 e0.30 0.012 f 1.7 0.067 g 0.6 0.024 h11.5 0.453 i 0.125 0.005 j8.51 0.335 lid #: 101-303-1, issue #:1
vitesse semiconductor corporation preliminary data sheet vsc7926 sdh/sonet 2.5gb/s laser diode driver g52188-0, rev 3.0 page 9 04/05/01 ? vitesse semiconductor corporation 741 calle plano camarillo, ca 93012 tel: (800) vitesse fax: (805) 987-5896 email: prodinfo@vitesse.com internet: www.vitesse.com package information - 24-pin ceramic package (straight leads) top view side view notes: drawing not to scale. package #: 101-000-0 issue #:1 1 2 3 4 5 6 78910 11 12 13 14 15 16 17 18 24 23 22 21 20 19 index a e a d i b hc c f g key mm in a 9.5 0.374 b 7.7 0.303 c 5.8 .230 d1.27 0.050 e0.30 0.012 f 1.7 0.067 g 0.6 0.024 h9.53 0.375 i 0.125 0.005 j8.51 0.335
vitesse semiconductor corporation preliminary data sheet vsc7926 sdh/sonet 2.5gbits/sec laser diode driver page 10 g52188-0, rev 3.0 04/05/01 ? vitesse semiconductor corporation 741 calle plano camarillo, ca 93012 tel: (800) vitesse fax: (805) 987-5896 email: prodinfo@vitesse.com internet: www.vitesse.com ordering information the order number for this product is formed by a combination of the device number, and package style. notice vitesse semiconductor corporation ( ? vitesse ? ) provides this document for informational purposes only. this document contains pre-production information about vitesse products in their concept, development and/or testing phase. all information in this document, includ ing descriptions of features, functions, performance, technical specifications and availability, is subject to change without notice at any time. n othing contained in this document shall be construed as extending any warranty or promise, express or implied, that any vitesse product will be availabl e as described or will be suitable for or will accomplish any particular task. vitesse products are not intended for use in life support appliances, devices or systems. use of a vitesse product in such appl ications without writ- ten consent is prohibited. vsc7926 xx device type vsc7926: 2.5gb/s laser diode driver package style kf: (ceramic - straight leads) kfl: (ceramic- formed leads) w: dice waffle pack
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