sy89645l precision low skew, 1-to-4 lvcmos/lvttl-to-lvds fanout buffer precision edge is a register ed trademark of micrel, inc. micrel inc. ? 2180 fortune drive ? san jose, ca 95131 ? usa ? tel +1 ( 408 ) 944-0800 ? fax + 1 (408) 474-1000 ? http://www.micrel.com general description the sy89645l is a 3.3v, fully differential, low skew, 1:4 lvds fanout buffer that ac cepts lvttl or lvcmos inputs. it is capable of processing clock signals as fast as 650mhz. the lvds signals are optimized to provide less than 40ps of output skew. the single-ended input takes a 3.3v lvttl or lvcmos, with a signal swing as small as 1.2v. the outputs are 280mv lvds, with fast rise and fall times, guaranteed to be less than 400ps. the sy89645l operates from a 3.3v + 5% power supply and is guaranteed over the full industrial temperature range (?40c to +85c). the sy89645l is part of micrel?s precision edge ? product line. data sheets and support documentation can be found on micrel?s web site at: www.micrel.com . block diagram precision edge ? features ? four identical lvds outputs ? clkin accepts lvcmos or lvttl input levels ? maximum output frequency: 650mhz ? translates lvcmos/lvttl input signals to lvds levels ? <40ps output-to-output skew ? <3ns propagation delay ? <400ps rise/fall times ? 3.3v 5% operating supply ? industrial temperature range: ?40c to +85c ? available in 20-pin tssop applications ? communications ? high-performance computing ? clock and data distribution markets ? datacom ? telecom ? storage ? ate ? test and measurement june 2011 m9999-060711 hbwhelp@micrel.com or (408) 955-1690
micrel, inc. sy89645l june 2011 3 m9999-060711 hbwhelp@micrel.com ordering information part number package type operating range package marking lead finish sy89645lk4g k4-20-1 industrial sy89645lk4g with pb-free bar-line indicator nipdau pb-free sy89645lk4gtr (2) k4-20-1 industrial sy89645lk4g with pb-free bar-line indicator nipdau pb-free notes: 1. contact factory for die availability. dice are guaranteed at t a = 25c, dc electricals only. 2. tape and reel. pin configuration 20-pin tssop (k4-20-1) pin description pin number pin name pin function 1, 9, 13 gnd power supply ground. 2 clk_en clock enable. when low, q outputs are forced low, /q outputs are forced high. the synchronous nature of the enable function forc es the output clocks to enable or disable following a rising and a falling edge of the input clock. when high, cl ock outputs follow input clock. internal 50k ? pull-up resistor. v th = v cc /2. see ?clock enable (clk_en) description? section. 3, 5, 6, 7, 8 nc no connect. 4 clkin lvcmos/lvttl clock input. this is the input to t he device. input accepts si ngle-ended input signals as small as 1.2v. v th = v cc /2. internal 50k ? pull-down resistor. 10, 18 vcc positive supply pins. connect to 3.3v supply, bypass with low esr capacitors, as close to pins as possible. 11, 12 14, 15 16, 17 19, 20 /q3, q3 /q2, q2 /q1, q1 /q0, q0 lvds differential output pairs: differential buffer ed copies of the input signal. the output swing is typically 280mv. normally terminated with 100 ? across the output pairs (q and /q). see ?lvds output termination? section. or (408) 955-1690
micrel, inc. sy89645l june 2011 4 m9999-060711 hbwhelp@micrel.com or (408) 955-1690 absolute maximum ratings (1) supply voltage (v cc )............................... ?0.5v to +4.6v input voltage (v in ) ............................ ?0.5v to v cc +0.3v lvds output current (i out )..................................10ma lead temperature (solde ring, 20sec .) .................. 260c storage temperature (t s ) ....................?65c to +150c operating ratings (2) supply voltage (v in )............................. +3.135v to +3.465v ambient temperature (t a ) ..........................?40c to +85c package thermal resistance (3) tssop junction-to-ambient ( ja ) still-air, multi-lay er board..............................75c/w junction-to-case ( jc )...........................................21c/w dc electrical characteristics (4) v dd = 3.3v 5%, t a = ?40 c to +85 c, unless otherwise stated. symbol parameter condition min. typ. max. units v cc positive supply voltage range 3.135 3.3 3.465 v i cc power supply current no load 43 60 ma lvcmos/lvttl dc electrical characteristics (4) v cc = 3.3v 5%, t a = ?40 c to +85 c, unless otherwise stated. symbol parameter condition min. typ. max. units v ih input high voltage clkin, clk_en 2 v cc +0.15 v v il input low voltage clkin, clk_en -0.3 0.8 v i ih input high current clkin clk_en v cc = v in = 3.465v v cc = v in = 3.465v 150 70 a i il input low current clkin clk_en v cc = 3.465v, v in = 0v v cc = 3.465v, v in = 0v -70 -150 a lvds outputs dc electrical characteristics (4) v cc = 3.3v 5%, r l = 100 ? across the outputs, t a = ?40 c to +85 c, unless otherwise stated. symbol parameter condition min. typ. max. units v out output voltage swing see figure 1a 200 280 mv v diff_out differential output voltage swing see figure 1b 400 560 mv v ocm output common mode vo ltage 1.125 1.25 1.375 v ? v ocm change in common mode voltage 5 25 mv notes: 1. permanent device damage may occur if absolute maximum ratings are exceeded. this is a stress rating only and functional ope ration is not implied at conditions other than those detailed in the operational sections of this data shee t. exposure to absolute maximum ratings co nditions for extended periods may affect device reliability. 2. the data sheet limits are not guaranteed if t he device is operated beyond the operating ratings. 3. jb and ja values are determined for a 4-layer board in still-air number, unless otherwise stated. 4. the circuit is designed to meet the dc specifications shown in the above table after thermal equilibrium has been establishe d.
micrel, inc. sy89645l june 2011 5 m9999-060711 hbwhelp@micrel.com ac electrical characteristics (5) v cc = +3.3v 5%, r l = 100 ? across the outputs, t a = ?40c to +85c, unless otherwise stated. symbol parameter condition min. typ. max. units f max maximum frequency v out > 140mv 650 mhz t pd propagation delay f max 650mhz, note 6 1.0 1.8 3.0 ns output skew note 7 40 ps t skew part-to-part skew note 8 500 ps t r, t f output rise/fall times (20% to 80%) f max 266mhz 150 250 400 ps f max 266mhz 45 55 % duty cycle f max > 266mhz 40 60 % notes: 5. all parameters measured at f max 650mhz, unless otherwise stated. 6. measured from v cc /2 of the input to the differential output crossing point. 7. defined as skew between outputs at the same supply voltage and with equal load conditions. measured at v cc /2 of the input to the differential output crossing point. 8. defined as skew between outputs on differ ent devices operating at the same suppl y voltages and with equal load conditions. u sing the same type of inputs on each device, the outputs are measured at the differential cross points. timing diagram clock enable (clk_en) description the enable function is synchronous so that the clock outputs will be enabled or disabled following a rising and a falling edge of the input clock. or (408) 955-1690
micrel, inc. sy89645l june 2011 6 m9999-060711 hbwhelp@micrel.com typical operating techniques v cc = 3.3v 5%; v in > 2v; t a = 25c, r l = 100 ? across output pair; unless otherwise stated. or (408) 955-1690
micrel, inc. sy89645l june 2011 7 m9999-060711 hbwhelp@micrel.com single-ended and di fferential swings figure 1a. single-ended voltage swing figure 1b. differential voltage swing or (408) 955-1690
micrel, inc. sy89645l june 2011 8 m9999-060711 hbwhelp@micrel.com lvds output interface applications lvds specifies a small swing of 280mv typical, on a nominal 1.25v common mode above ground. the common mode voltage has tight limits to permit large variations in ground between an lvds driver and receiver. also, change in common mode voltage, as a function of data input, is kept to a minimum, to keep emi low. figure 2a. lvds differential measurement figure 2b. lvds common-mode measurement or (408) 955-1690
micrel, inc. sy89645l june 2011 9 m9999-060711 hbwhelp@micrel.com package information 20-pin tssop (mm) micrel, inc. 2180 fortune drive san jose, ca 95131 usa tel +1 (408) 944-0800 fax +1 (408) 474-1000 web http://www.micrel.com micrel makes no representations or warranties with respect to t he accuracy or completeness of the information furnished in this data sheet. this information is not intended as a warranty and micrel does not assume responsibility for it s use. micrel reserves the right to change circuitry, specifications and descriptions at any time without notice. no license, whether expre ss, implied, arising by estoppel or other wise, to any intellectual property rights is granted by this document. except as provided in micrel?s terms and conditions of sale for such products, mi crel assumes no liability whatsoever, and micrel disclaims any express or implied warranty relating to the sale and/or use of micrel products including l iability or warranties relating to fitness for a particular purpose, merchantability, or infringement of an y patent, copyright or other intellectual p roperty right. micrel products are not designed or authori zed for use as components in life support app liances, devices or systems where malfu nction of a product reasonably be expected to result in pers onal injury. life support devices or system s are devices or systems that (a) are in tended for surgical impla into the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significan t injury to the user. a purchaser?s use or sale of micrel produc ts for use in life support app liances, devices or systems is a purchaser?s own risk and purchaser agrees to fully indemnify micrel for any damages resulting from such use or sale. can nt ? 2006 micrel, incorporated. or (408) 955-1690
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