________________________________________________________________ _ maxim integrated products _ _ 1 for pricing, delivery, and ordering information, please contact maxim direct at 1-888-629-4642, or visit maxims website at www.maxim-ic.com. spread-spectrum clock generators max31c80/max31d80 general description the max31c80/max31d80 are spread-spectrum clock generators that contain a phase-locked loop (pll) that generates a 2mhz to 134mhz clock from an input clock or crystal. the pll can provide a spread-spec - trum down-dithered (max31d80) or center-dithered (max31c80) frequency-modulated clock. the devices also buffer the incoming clock and provide this output on a separate pin. the max31c80/max31d80 are provided in a 10-pin tdfn package and operate over a full -40 n c to +125 n c automotive temperature range. devices can be factory programmed for multiple combinations of input and out - put frequencies (see the ordering information table). a low-cost, low-frequency crystal can be used at the input to generate frequencies up to 134mhz. features s 2mhz_ to_ 134mhz_ spread-spectrum_ clock_ generator s input_ can_ be_ either_ an_ 8mhz_ to_ 34mhz_ crystal_ or_ 8mhz_ to_ 134mhz_ clock s factory-programmable_ output_ frequencies_ in_ 2mhz_ to_ 134mhz_ range s low-cost_ crystal_ at_ low_ frequency_ used_ to_ generate_ high_ frequencies s on-board_ pll_ is_ capable_ of_ spread-spectrum_ frequency_ modulation s down-_ or_ center-dither_ spread-spectrum_ frequency_ modulation s user-configurable_ spread-spectrum_ dither_ magnitude s low_ cycle-to-cycle_ jitter s 3.3v_ supply_ voltage s temperature_ range:_ -40 n c_ to_ +125 n c s small_ package:_ 10-pin_ tdfn_ (3mm_ x_ 3mm_ x_ 0.8mm) applications graphics cards set-top boxes automotive infotainment printers 19-5214; rev 0; 4/10 ordering information xxx = factory-programmable output frequency and dither rate (see the selector guide table). + denotes a lead(pb)-free/rohs-compliant package. t = tape and reel. * ep = exposed pad. selector guide appears at end of data sheet. part temp_ range dither_ mode pin-package max31c80 t-xxx+ -40 n c to +125 n c center 10 tdfn-ep* max31c80t-xxx+t -40 n c to +125 n c center 10 tdfn-ep* max31d80 t-xxx+ -40 n c to +125 n c down 10 tdfn-ep* max31d80t-xxx+t -40 n c to +125 n c down 10 tdfn-ep* typical application circuit max31d80 x1 smsel1 smsel0 gnd x2 xout 27mhz clock decoupling capacitor f in = 27mhz v cc f in = 27mhz clkout v cc f clkout = 100mhz 1.5% down dithered v cc
spread-spectrum clock generators max31c80/max31d80 2 _ _ _______________________________________________________________________________________ stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. these are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. exposure to absolute maximum rating conditions for extended periods may affect device reliability. voltage range on v cc relative to gnd .............. -0.3v to +4.3v voltage range on any other pin relative to gnd .................................... -0.3v to (v cc + 0.3v)* continuous power dissipation (t a = +70c) 10-pin tdfn (derate 24.4mw/c above +70c) ..... 1951.2mw storage temperature range ............................ -55 n c to +135 n c lead temperature (soldering, 10s) ................................ +300 n c soldering temperature (reflow) ...................................... +260 n c recommended_ operating_ conditions (t a = -40 n c to +125 n c.) absolute_ maximum_ ratings * not to exceed +4.3v. parameter symbol conditions min typ max units supply voltage v cc 3.0 3.3 3.6 v input logic 0 (smsel0 and smsel1) v il -0.3 0.25 x v cc v input logic 1 (smsel0 and smsel1) v ih 0.75 x v cc v cc + 0.3 v input logic unconnected (smsel0 and smsel1) v if limits are in case user wants to force voltage instead of unconnecting this pin 0.4 x v cc 0.55 x v cc v input logic 0 for x1 v il:x1 -0.3 0.3 x v cc v input logic 1 for x1 v ih:x1 0.7 x v cc v cc + 0.3 v xout load c l:xout 15 pf clkout load c l:clkout 2mhz p f clkout < 67mhz 15 pf 67mhz p f clkout < 101mhz 10 101mhz p f clkout p 134mhz 7 crystal frequency f in 8 34 mhz clock input frequency f in 8 134 mhz crystal esr x esr 90 i clock input duty cycle f indc 40 60 % crystal parallel load capacitance c cl 18 pf
spread-spectrum clock generators max31c80/max31d80 _______________________________________________________________________________________ _ _ 3 dc_ electrical_ characteristics (3.0v p v cc p 3.6v, t a = -40 n c to +125 n c, unless otherwise noted.) ac_ electrical_ characteristics (3.0v p v cc p 3.6v, t a = -40 n c to +125 n c, unless otherwise noted.) parameter symbol conditions min typ max units supply current i dd f in = 27mhz, f clkout = 100mhz, down dithered, c l = 10pf 22 ma input leakage (smsel0 and smsel1) i il smsel_ = gnd or v cc q 15 f a low-level output voltage (xout and clkout) v ol i ol = 10ma 0.2 v high-level output voltage (xout and clkout) v oh i oh = -10ma v cc - 0.2 v input capacitance (x1 and x2) c in 5 pf parameter symbol conditions min typ max units clkout duty cycle f clkout:dc c l:clkout = 7pf 40 60 % xout duty cycle f xout:dc c l:xout = 7pf, t a = +25 n c, v cc = 3.3v 40 60 rise time t r c l:clkout = 7pf 1.6 ns fall time t f c l:clkout = 7pf 1.6 ns dither rate range f dr factory programmable 20 40 khz dither rate accuracy -4 +4 % peak cycle-to-cycle jitter t j clkout = 100mhz, 10,000 cycles, t a = +25 n c 75 ps power-up time t pup v cc valid to output active, t a = +25 n c, v cc = 3.3v 1 ms
spread-spectrum clock generators max31c80/max31d80 4 _ _ _______________________________________________________________________________________ typical operating characteristics (v cc = +3.3v, t a = +25c, unless otherwise noted.) frequency spectrum at 100mhz with down dither max31c80 toc07 frequency (mhz) attenuation (db) 100 98 -50 -40 -30 -20 -10 0 -60 96 f clkout = 100mhz center dither = -3% -16.56db frequency spectrum at 122mhz with center spread max31c80 toc06 frequency (mhz) attenuation (db) 123.2 121.2 -50 -40 -30 -20 -10 0 -60 119.2 f clkout = 122mhz center dither = 1.5% -14.23db duty cycle vs. temperature max31c80 toc05 temperature (c) duty cycle (%) 110 60 10 42 44 46 48 50 52 54 56 58 60 40 -40 f clkout = 100mhz v cc = 3.6v v cc = 3.3v v cc = 3.0v duty cycle vs. supply voltage max31c80 toc04 supply voltage (v) duty cycle (%) 3.4 3.2 42 44 46 48 50 52 54 56 58 60 40 3.0 3.6 f clkout = 100mhz t a = +125c t a = +25c t a = -40c supply current vs. output frequency max31c80 toc03 output frequency (mhz) supply current (ma) 104 80 56 32 5 10 15 20 25 0 8 v cc = 3.3v supply current vs. temperature max31c80 toc02 temperature (c) supply current (ma) 110 85 -15 10 35 60 17 19 21 23 25 27 29 15 -40 f in = 27mhz f clkout = 100mhz v cc = 3.6v v cc = 3.3v v cc = 3.0v supply current vs. supply voltage max31c80 toc01 supply voltage (v) supply current (ma) 3.4 3.2 17 19 21 23 25 27 15 3.0 3.6 f in = 27mhz f clkout = 100mhz t a = +125c t a = +25c t a = -40c
spread-spectrum clock generators max31c80/max31d80 _______________________________________________________________________________________ _ _ 5 pin configuration 1 3 4 10 8 7 x2 v cc gnd x1 v cc gnd 2 9 smsel1 + smsel0 ep 5 6 xout clkout tdfn top view max31c80 max31d80 crystal oscillator programmable pll with spread spectrum spread-spectrum magnitude control clkout (f clkout = 2mhz to 134mhz) xout (f xout = f in ) v cc f in gnd v cc x1 x2 smsel0 smsel1 8mhz to 134mhz clock or 8mhz to 34mhz crystal max31c80 max31d80 pin name function 1 x1 crystal drive/clock input. a crystal with the proper loading is connected across x1 and x2. instead of a crystal, a clock can be applied at the x1 input. if no clock or crystal is present, then no clock is output at either xout or clkout. 2, 9 smsel0, smsel1 spread-spectrum magnitude select. these are three-state digital inputs to determine the spread-spectrum magnitude. tables 1 and 2 provide details for configuration of these pins for down and center dither, respectively. pin name function 3, 8 v cc supply voltage 4, 7 gnd ground 5 clkout clock output. spread-spectrum-capable digital output clock from the pll. 6 xout crystal buffered output. buffered digital output of the input crystal or clock. 10 x2 crystal drive output. a crystal with the proper loading is connected across x1 and x2. if a clock is applied at the x1 input, then x2 should be left open circuit. ep exposed pad. connect to gnd. block diagram pin description
spread-spectrum clock generators max31c80/max31d80 6 _ _ _______________________________________________________________________________________ detailed description the max31c80/max31d80 modulate an input clock to generate a center-dithered or down-dithered spread- spectrum output. an 8mhz to 27mhz crystal or 8mhz to 134mhz oscillator input is applied to the device. an internal pll dithers the output clock at a user-select - able magnitude to produce a down-dithered or center- dithered output clock. the output clocks frequency is programmable from 2mhz to 134mhz. the devices also buffer the incoming clock and provide this output on a separate pin. spread-spectrum dither magnitude the max31d80 can generate down-dithered magnitudes up to -3%. the max31c80 can generate center-dithered magnitudes up to p 1.5%. the desired magnitude is selected using the input pins smsel1 and smsel0 as shown in tables 1 and 2. a power cycle is required after each change of the dither magnitude for the changes to take effect. table_ 1._ spread-spectrum_ mode_ and_ magnitude_ select_ (for_ down_ dither) table_ 2._ spread-spectrum_ mode_ and_ magnitude_ select_ (for_ center_ dither) smsel1 smsel0 spread-spectrum_magnitude_ selected_(%) spread-spectrum_dither_mode_ selected 0 0 spread-spectrum disabled 0 unconnected 0 to -0.25 down dither 0 1 0 to -0.375 unconnected 0 0 to -0.5 unconnected unconnected 0 to -0.75 unconnected 1 0 to -1.0 1 0 0 to -1.5 1 unconnected 0 to -2.0 1 1 0 to -3.0 smsel1 smsel0 spread-spectrum_ magnitude_ selected_ (%) spread-spectrum_ dither_ mode_ selected 0 0 spread-spectrum disabled 0 unconnected -0.25 to +0.25 center dither 0 1 -0.375 to +0.375 unconnected 0 -0.5 to +0.5 unconnected unconnected -0.75 to +0.75 unconnected 1 -1.0 to +1.0 1 0 -1.5 to +1.5 1 unconnected n/a 1 1 n/a
spread-spectrum clock generators max31c80/max31d80 _______________________________________________________________________________________ _ _ 7 figure 1. spread-spectrum frequency modulation (down dithered) figure 2. spread-spectrum frequency modulation (center dithered) f clkout f clkout - (0.25% to 3%) down dithered (max31d80) if smsel0 = smsel1 = 0 frequency time dither amount (-0.25% to -3.0%) 1 dither cycle rate f clkout + (0.25% to 1.5%) f clkout - (0.25% to 1.5%) f in center dithered (max31c80) if smsel0 = smsel1 = 0 frequency time dither amount (0.25% to 1.5%) 1 dither cycle rate
spread-spectrum clock generators max31c80/max31d80 8 _ _ _______________________________________________________________________________________ factory programmability the max31c80/max31d80 can provide a variety of fre - quencies, which are available to users by ordering the device according to specifications listed in the selector guide table. email the factory at custom.oscillators@maxim-ic.com to obtain custom output frequencies for specific input frequencies not mentioned in the selector guide table. applications information power-supply decoupling to achieve best results, it is highly recommended that a decoupling capacitor be used on the ic power-supply pins. typical values of decoupling capacitors are 0.01 f f and 0.1 f f. use a high-quality, ceramic, surface-mount capacitor and mount it as close as possible to the v cc pins of the ic to minimize lead inductance. v cc v cc valid output valid output valid t pup xout clkout figure 3. power-up timing selector guide + denotes a lead(pb)-free/rohs-compliant package. package information for the latest package outline information and land patterns, go to www.maxim-ic.com/packages . note that a +, #, or - in the package code indicates rohs status only. package drawings may show a different suffix character, but the drawing pertains to the package regardless of rohs status. package_ type package_ code document_ no. 10 tdfn-ep t1033+1 21-0137 part input_ frequency_ (mhz) output_ frequency_ (mhz) dither_ rate_ (khz) dither_ type max31c80 t-ugq+ 27 100 31.25 center max31c80t-002+ 25 63.05 32.05 center max31d80 t-ugq+ 27 100 31.25 down max31d80t-003+ 12 12 25 down
spread-spectrum clock generators max31c80/max31d80 maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a maxim product. no circuit patent licenses are implied. maxim reserves the right to change the circuitry and specifications without notice at any time. maxim integrated products, 120 san gabriel drive, sunnyvale, ca 94086 408-737-7600 9 ? 2010 maxim integrated products maxim is a registered trademark of maxim integrated products, inc. revision history revision number revision date description pages changed 0 4/10 initial release
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