general description the DS1083L is a spread-spectrum clock modulator ic that reduces emi in high-clock, frequency-based, digi- tal electronic equipment. using an integrated phase-locked loop (pll), the DS1083L accepts an input clock signal in the range of 16mhz to 134mhz and delivers a spread-spectrum modulated output clock signal. the pll modulates, or dithers, the output clock about the center input frequen- cy at a pin-selectable magnitude. the DS1083L auto- matically adjusts the dither rate based on the input clock frequency to maximize the emi reduction. by dithering the system clock, all the address, data, and timing signals generated from this signal are also dithered so that the measured emi at the fundamental and harmonic frequencies is greatly reduced. this is accomplished without changing clock rise/fall times or adding the space, weight, design time, and cost asso- ciated with mechanical shielding. the DS1083L is provided in a low-cost, space-saving, 6-lead thin sot23 package and operates over a full automotive temperature range of -40? to +125?. applications lcd panels for tvs, desktop monitors, notebook and tablet pcs automotive telematics and infotainment printers features ? modulates a 16mhz to 134mhz clock with center spread-spectrum dithering ? selectable spread-spectrum modulation magnitudes of: ?.5% ?% ?.5% ?% ? low 75ps cycle-to-cycle jitter ? automatic dither cycle rate adjustment to maximize emi reduction ? low cost ? low power consumption ? 3.3v single voltage supply ? -40? to +125? operating temperature range ? small 6-lead thin sot23 package DS1083L 16mhz to 134mhz spread-spectrum clock modulator for lcd panels rev 0; 5/07 ________________________________________________________________ maxim integrated products 1 for pricing, delivery, and ordering information, please contact maxim direct at 1-888-629-4642, or visit maxim? website at www.maxim-ic.com. + denotes a lead-free package. t = tape and reel. ordering information part temp range pin-package DS1083Lr+t -40c to +125c 6 thin sot23 block diagram gnd sso pll with center- spread dithering configuration decode and control smsel1 clkin smsel2 r pu clock rate detect v cc r pu f sso = 16mhz to 134mhz (dithered) v cc vcc f in = 16mhz to 134mhz DS1083L pin configuration and typical operating circuit appear at end of data sheet. ________________________________________________________________ maxim integrated products 1 for pricing, delivery, and ordering information, please contact maxim direct at 1-888-629-4642, or visit maxim? website at www.maxim-ic.com.
absolute maximum ratings recommended operating conditions (t a = -40? to +125?, unless otherwise noted.) stresses beyond those listed under ?bsolute maximum ratings?may cause permanent damage to the device. these are stress rating s only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specificatio ns is not implied. exposure to absolute maximum rating conditions for extended periods may affect device reliability. voltage range on vcc relative to gnd.............-0.5v to +3.63v voltage range on any lead relative to gnd ................-0.5v to (v cc + 0.5v), not to exceed +3.63v operating temperature range .........................-40? to +125? storage temperature range .............................-55? to +125? soldering temperature...........................refer to the ipc/jedec j-std-020 specification. parameter symbol conditions min typ max units v cc supply voltage v cc (note 1) 3.0 3.6 v smsel1/smsel2 input logic 1 v ih 0.7 x v cc v cc + 0.3 v smsel1/smsel2 input logic 0 v il -0.3 0.3 x v cc v f sso < 80mhz 15 sso load c l 80mhz f sso < 134mhz 7 pf clkin frequency f in 16 134 mhz clkin duty cycle f indc 40 60 % v cc power-up time t pv gnd to v ccmin 200 ms dc electrical characteristics (v cc = +3.0v to +3.6v, t a = -40? to +125?, unless otherwise noted.) parameter symbol conditions min typ max units supply current i cc c l = 7pf, f in = 134mhz 15 ma smsel1/smsel2 pullup resistance r pu t a = +25c 60 100 140 k smsel1/smsel2 input leakage i il 0v < v in < v cc 80 a low-level output voltage (sso) v ol i ol = 4ma 0.4 v high-level output voltage (sso) v oh i oh = -4ma 2.4 v ac electrical characteristics (v cc = +3.0v to +3.6v, t a = -40? to +125?, unless otherwise noted.) parameter symbol conditions min typ max units sso duty cycle f ssodc measured at v cc /2 40 60 % sso rise time t r c l = 7pf 1 ns sso fall time t f c l = 7pf 1 ns peak cycle-to-cycle jitter t j t a = -40c to +85c, 10,000 cycles 75 ps DS1083L 16mhz to 134mhz spread-spectrum clock modulator for lcd panels 2 _______________________________________________________________________________________ note 1: all voltages referenced to ground. currents into the ic are positive and currents out of the ic are negative.
DS1083L 16mhz to 134mhz spread-spectrum clock modulator for lcd panels supply current vs. supply voltage DS1083L toc01 supply voltage (v) supply current (ma) 3.5 3.4 3.3 3.2 3.1 2 4 6 8 10 12 0 3.0 3.6 clkin = 134mhz clkin = 16mhz clkin = 66mhz typical operating characteristics (t a = +25?, unless otherwise noted.) _______________________________________________________________________________________ 3 supply current vs. temperature DS1083L toc02 temperature ( c) supply current (ma) 100 80 60 40 20 0 -20 2 4 6 8 10 12 0 -40 120 clkin = 134mhz clkin = 16mhz clkin = 66mhz supply current vs. frequency DS1083L toc03 frequency (mhz) supply current (ma) 116 96 76 56 36 2 4 6 8 10 12 0 16 134 v cc = 3.6v v cc = 3.0v duty cycle vs. temperature DS1083L toc04 temperature ( c) duty cycle (%) 120 100 60 80 0 20 40 -20 42 44 46 48 50 52 54 56 58 60 40 -40 clkin = 66mhz duty cycle vs. supply voltage DS1083L toc05 supply voltage (v) duty cycle (%) 3.5 3.4 3.3 3.2 3.1 42 44 46 48 50 52 54 56 58 60 40 3.0 3.6 clkin = 66mhz spectrum attenuation vs. frequency at different dither amplitudes DS1083L toc06 frequency (mhz) attenuation (db) f out = 40mhz 2% 1.5% 0.5% 4.5db 3db 1% f out = 40mhz rbw = 120khz center dither 6db
detailed description the DS1083L modulates an input clock to provide a cen- ter-dithered spread-spectrum output. a 16mhz to 134mhz clock is applied to the clkin pin. the pll dithers the output clock about its center frequency at a user-selectable magnitude. the user is required to cycle power to the device each time there is a change in the input frequency, for the pll to lock correctly. this ensures proper output frequency and dither rate. the desired spread-spectrum magnitude is selected using input pins smsel1 and smsel2 (see the pin description for details). the DS1083L is capable of generating spread-spectrum clocks from 16mhz to 134mhz. dither-rate selection the output spread-spectrum dither rate is automatically adjusted depending on the input frequency, to maxi- mize emi reduction. the dither cycle rate is: f in /512, if f in is between 16mhz and 33mhz f in /1024, if f in is between 33mhz and 64mhz f in /2048, if f in is between 64mhz and 134mhz on power-up, the output clock (sso) remains three- stated until it reaches a stable frequency (f sso ). the dither rate is selected by sampling the input clock at power-up. applications information power-supply decoupling to achieve best results, it is highly recommended that a decoupling capacitor is used on the ic power-supply pins. typical values of decoupling capacitors are 0.01? and 0.1?. use a high-quality, ceramic, surface- mount capacitor, and mount it as close as possible to the vcc and gnd pins of the ic to minimize lead inductance. chip information substrate connected to ground DS1083L 16mhz to 134mhz spread-spectrum clock modulator for lcd panels 4 _______________________________________________________________________________________ pin description pin name description 1 clkin clock input. 16mhz to 134mhz clock input (f in ). 2 gnd ground 3 sso spread-spectrum clock output. outputs a center-dithered spread-spectrum version of the clock input at clkin. spread-spectrum magnitude select inputs. these digital inputs select the desired spread-spectrum magnitude as shown in the table below. both inputs contain pullup resistors (r pu ) to v cc . smsel2 smsel1 magnitude selected (%) 4 smsel2 0 0 2 0 1 1.5 1 0 1 5smsel1 1 1 0.5 6 vcc supply voltage
DS1083L 16mhz to 134mhz spread-spectrum clock modulator for lcd panels maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a maxim product. no circu it 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 _____________________ 5 2007 maxim integrated products is a registered trademark of maxim integrated products, inc. f in + (0.5%, 1%, 1.5%, or 2% of f in ) f in f in - (0.5%, 1%, 1.5%, or 2% of f in ) f sso time 1 dither cycle rate* if dither amount = 0% dither amount ( 0.5%, 1%, 1.5%, or 2%) *dither cycle rate = f in /512, if f in = 16mhz to 33mhz f in /1024, if f in = 33mhz to 64mhz f in /2048, if f in = 64mhz to 134mhz figure 1. spread-spectrum frequency modulation gnd smsel2 sso 1 6 vcc 5 smsel1 clkin thin sot23 top view 2 34 DS1083L + pin configuration clkin gnd sso smsel1 vcc decoupling capacitor v cc f sso smsel2 f in = 16mhz to 134mhz dithered note: in the above configuration with smsel1 connected to vcc and smsel2 connected to gnd, the device will have a spread-spectrum magnitude of 1.5%. DS1083L typical operating circuit package information for the latest package outline information, go to www.maxim-ic.com/packages . package type document no. 6 thin sot23 21-0114
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