description 3.3v and 5v power supply options up to 2.5gbps operation 30ma modulation current separate modulation control separate output enable for laser safety differential inputs for data 75k ? input pulldown resistor available in a tiny 10-pin (3mm) msop the SY88922V is a high speed current switch for driving a semiconductor laser diode in optical transmission applications. the output current, or modulation current i mod , is dc current controlled by i rset , current through the resistor r set . the output out is high when output enable is high. the device incorporates complementary open collector outputs with a capability of driving peak current of 30ma. the resistor r ext must be placed between /out and v cc to dissipate the worst case power. r ser is recommended to compensate for laser diode matching issues. pin 9 and pin 10 should be connected to achieve better performance. the SY88922V utilizes the high performance bipolar asset technology. features 5v/3.3v 2.5gbps laser diode driver pin configurations block diagram SY88922V final 1.25gbps and 2.5gpbs gigabit ethernet 531mbps, 1062mbps and 2.12gbps fibre channel 622mbps sonet gigabit interface converter 2.5gbps sdh/sonet 2.5gbps proprietary links applications 1 /en d in /d in v ref r set 10 out out /out gnd v cc 9 8 7 6 2 3 4 5 msop k10-1 d in v cc r ext /out out r ser to laser diode /d in modulation control internal logic bias control /en i mod v ref 40x r set gnd v cc gnd r set 1 rev.: b amendment: /0 issue date: august 2000
2 SY88922V micrel pin function v cc most positive power supply input. gnd ground d in , /d in these differential pecl 100k compatible inputs receive nrz data. /en this pecl 100k compatible input enables laser driver. modulation current goes to zero when asserted high. out, /out open collector outputs from the modulation buffer drive these differential current outputs. v ref voltage reference for use with r set . r set an external resistor sets up the source current for modulation i mod . d /d /en out (2) /out lhlhl hlllh xxhhl notes: 1. l = low, h = high, x = don't care 2. h = i out = 0ma pin names truth table (1) symbol rating value unit v cc power supply voltage 0 to +7.0 v v i input voltage 0 to v cc v i o output current 25 ma t a operating temperature range 40 to +85 c t store storage temperature range 55 to +125 c p tot power dissipation 250 mw absolute maximum ratings (1) note: 1. permanent device damage may occur if absolute maximum ratings are exceeded. this is a stress rating only and functional oper ation is not implied at conditions other than those detailed in the operational sections of this data sheet. exposure to absolute maximum ratlng co nditions for extended periods may affect device reliability. symbol rating value unit v cc power supply voltage +4.5 to +5.5 (or) +3.0 to +3.6 v r ext resistor to dissipate power 10 to 50 ? r ser laser diode serial resistor 0 to 50 ? r set (3) resistor to adjust current 700 to 20,000 ? ja thermal resistance of package to ambient (2) 113 c/w c out capacitance on out + /out 2.5 typical pf notes: 1. the voltage drop across r ext and r ser plus laser diode should not be greater than 1v. 2. still air without heatsink. 3. r set minimum 430 ? . operating conditions (1)
3 SY88922V micrel t a = ?0 ct a = 0 ct a = +25 ct a = +85 c symbol parameter min. typ. max. min. typ. max. min. typ. max. min. typ. max. unit t pd d propagation delay 400 ps d in out t pd en propagation delay 400 ps /en out t r rise/fall time (2) 78 130 76 130 74 130 72 130 ps t f (20% to 80%) i or output current ringing (2) 10 10 10 10 % t a = ?0 ct a = 0 ct a = +25 ct a = +85 c symbol parameter min. max. min. max. min. typ. max. min. max. unit v ih input high voltage v cc 1165 v cc 880 v cc 1165 v cc 880 v cc 1165 v cc 880 v cc 1165 v cc 880 mv (d in , /d in , /en) v il input low voltage v cc 1810 v cc 1475 v cc 1810 v cc 1475 v cc 1810 v cc 1475 v cc 1810 v cc 1475 mv (d in , /d in , /en) v ref reference voltage 1.7 2.3 1.7 2.3 1.7 2.0 2.3 1.7 2.3 v i il input low current (1) 0.5 0.5 0.5 0.5 ua (d in , /d in , /en) 300 300 300 300 i ih input high current 100 100 100 100 ua (d in , /d in , /en) i cc supply current (2) 25 25 25 25 ma i ol output low current 1000 1000 450 1000 1000 ua (/en = high) i out modulation current 30 30 30 30 ma i rset modulation control 0.125 0.625 0.125 0.625 0.125 0.125 0.125 0.625 ma a rset =i out /i rset 30 44 30 44 30 38 30 30 44 d j deterministic jitter (3) 7 ps (rms) notes: 1. v i = v il (min.) 2. i mod = 25ma. 3. i mod = 10ma, 2.5gbps, 2 33 1 pattern. dc electrical characteristics gnd = 0v; v cc = +5.0v 10% or v cc = +3.3v 10% notes: 1. r ext = r ser = 25 ? 1%, r ser connects to v cc directly without laser diode. 2. i mod = 10ma. 3. i oh = 5 to 25ma. ac electrical characteristics (1) i mod =10ma; gnd = 0v; v cc = +5v 10% or v cc = +3.3v 10%
4 SY88922V micrel typical characteristics 0 10 20 30 40 0.0 1.0 2.0 3.0 4.0 5.0 i oh ( a) rset (k ? ) i oh vs. r set r tol = 1.0 t a = 55 c v cc = 3.3v v cc = 5.0v figure 1. dc response product ordering code ordering package operating code type range SY88922Vkc k10-1 commercial SY88922Vkctr k10-1 commercial
5 SY88922V micrel 10 lead msop (k10-1) rev. 00 micrel-synergy 3250 scott boulevard santa clara ca 95054 usa tel + 1 (408) 980-9191 fax + 1 (408) 914-7878 web http://www.synergysemi.com http://www.micrel.com this information is believed to be accurate and reliable, however no responsibility is assumed by micrel for its use nor for an y infringement of patents or other rights of third parties resulting from its use. no license is granted by implication or otherwise under any patent or pat ent right of micrel inc. ? 2000 micrel incorporated
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