general description the ds1091l is a low-cost clock generator that is factory- trimmed to output frequencies from 130khz to 66.6mhz with a nominal accuracy of ?.25%. the device can also produce a center- or down-dithered spread-spectrum out- put with pin-selectable dither magnitude and rate. assembled in an 8-pin ?ax package, the ds1091l is designed to operate with a 3.0v to 3.6v power supply over the automotive temperature range (-40? to +125?). applications automotive infotainment pos terminals lcd displays printers industrial control features ? spread-spectrum clock output from 130khz to 66.6mhz ? operating temperature range of -40c to +125c ? accuracy of 1.75% across temperature and voltage ? factory trimmed ? center-dithered (ds1091la) or down-dithered (ds1091lb) spread-spectrum output ? pin-selectable center-dither magnitude of 0%, 1%, 2%, or 4% ? pin-selectable down-dither magnitude of 0%, -2%, -4%, or -8% ? pin-selectable dither rate ? 3.0v to 3.6v supply operation ? lead-free 8-pin max package ds1091l automotive temperature range spread-spectrum econoscillator ______________________________________________ maxim integrated products 1 1 2 3 4 8 7 6 5 dr n.c. n.c. sel0 sel1 gnd v cc out max top view ds1091l pin configuration 8 3 4 2 1 out dr 8 max ds1091l v cc v cc f out decoupling capacitors 7 6 5 sel0 v cc n.c. n.c. sel1 gnd v cc typical operating circuit rev 1; 6/07 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/rohs-compliant package. xxx denotes factory-programmed custom frequencies. visit www.maxim-ic.com/support for information/questions concerning custom frequencies. ?ax is a registered trademark of maxim integrated products, inc. ordering information part temp range pin-package spread spectrum output frequency (mhz) DS1091LUA-027+ -40? to +125? 8 ?ax center 27.0 ds1091lua-033+ -40? to +125? 8 ?ax center 33.3 ds1091lua-066+ -40? to +125? 8 ?ax center 66.6 ds1091lua-xxx+ -40? to +125? 8 ?ax center custom (contact factory) ds1091lub-027+ -40? to +125? 8 ?ax down 27.0 ds1091lub-033+ -40? to +125? 8 ?ax down 33.3 ds1091lub-066+ -40? to +125? 8 ?ax down 66.6 ds1091lub-xxx+ -40? to +125? 8 ?ax down custom (contact factory)
absolute maximum ratings recommended operating conditions (t a = -40? to +125?.) 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 on v cc relative to ground.......................-0.5v to +6.0v voltage on dr, sel0, sel1 relative to ground* ..............................................-0.5v to (v cc + 0.5v) operating temperature range .........................-40? to +125? storage temperature range .............................-55? to +125? soldering temperature...................see j-std-020 specification parameter symbol conditions min typ max units supply voltage v cc (note 1) 3.0 3.3 3.6 v high-level input voltage (sel0, sel1, dr) v ih 0.7 x v cc v cc + 0.3 v low-level input voltage (sel0, sel1, dr) v il -0.3 0.3 x v cc v dc electrical characteristics (t a = -40? to +125?; v cc = +3.0v to +3.6v, unless otherwise noted.) parameter symbol conditions min typ max units high-level output voltage (out) v oh i oh = -4ma, v cc = 3.0v 2.4 v low-level output voltage (out) v ol i ol = 4ma 0.4 v high-level input current (sel0, sel1, dr) i ih v cc = 3.6v 1 a low-level input current (sel0, sel1, dr) i il v il = 0 -1 a supply current (active) i cc (note 2) 16 ma * this voltage must not exceed 6.0v. ac electrical characteristics (t a = -40? to +125?; v cc = +3.0v to +3.6v, unless otherwise noted.) parameter symbol conditions min typ max units output frequency range f out (note 3) 0.130 66.6 mhz v cc = 3.3v, t a = +25 c -0.25 0 +0.25 across t a and v cc -1.75 +1.75 output center frequency tolerance f out 0? to +70?, across v cc -1.2 +1.2 % power-up time t pu (note 4) 0.1 ms load capacitance c l 15 50 pf ds1091l automotive temperature range spread-spectrum econoscillator 2 _____________________________________________________________________
ds1091l automotive temperature range spread-spectrum econoscillator _____________________________________________________________________ 3 note 1: all voltages are referenced to ground. currents entering the ic are specified positive and currents exiting the ic are negative . note 2: supply current measured with c l = 15pf, v cc = 3.6v, t a = 25?, f out = 66.6mhz, no dither. note 3: no dither. note 4: guaranteed by design. note 5: for aging characteristics, contact factory. typical operating characteristics (t a = +25?, v cc = 3.3v, unless otherwise noted.) ac electrical characteristics (continued) (t a = -40? to +125?; v cc = +3.0v to +3.6v.) parameter symbol conditions min typ max units < 33.3mhz (note 3) 50 duty cycle 33.3mhz (note 3) 40 60 % jitter (rms), 50mhz 0.3 % 7.4 7.8 7.6 8.4 8.2 8.0 9.0 8.8 8.6 9.2 -40 20 -10 50 80 110 i cc vs. temperature ds1091l toc01 temperature ( c) i cc (ma) v cc = 3.6v v cc = 3.3v v cc = 3.0v -1.75 -0.75 -1.25 0.25 -0.25 1.25 0.75 1.75 -40 20 50 -10 80 110 frequency variation (%) vs. temperature ds1091l toc02 temperature ( c) frequency variation (%) v cc = 3.3v no dither f out = 130khz f out = 66mhz -0.25 -0.10 -0.15 -0.20 -0.05 0.00 0.05 0.10 0.15 0.20 0.25 3.0 3.2 3.1 3.3 3.4 3.5 3.6 frequency variation (%) vs. voltage ds1091l toc03 v cc (v) frequency variation (%) f out = 66mhz f out = 130khz no dither 48.0 48.5 49.0 49.5 50.0 50.5 51.0 51.5 52.0 3.0 3.2 3.1 3.3 3.4 3.5 3.6 duty cycle vs. v cc ds1091l toc04 v cc (v) duty cycle (%) f out = 66mhz f out = 130khz no dither 40 46 44 42 50 48 58 56 54 52 60 -40 -15 10 35 60 85 110 duty cycle vs. temperature ds1091l toc05 temperature ( c) duty cycle (%) f out = 66mhz f out = 130khz no dither
ds1091l automotive temperature range spread-spectrum econoscillator 4 _____________________________________________________________________ typical operating characteristics (continued) (t a = +25?, v cc = 3.3v, unless otherwise noted.) pin description pin ?ax8 name function 1 out spread-spectrum clock output 2v cc supply voltage 3 gnd ground 4 sel1 5 sel0 spread spectrum dither magnitude select inputs. selects dither magnitude (see table 1). 6, 7 n.c. no connection 8 dr spread-spectrum dither rate selector. selects dither rate (see table 2). 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 output fall time ds1091l toc07 time (ns) output (v) fall time = 1.13ns typical at 12pf load -35 -30 -25 -20 -15 -10 -5 0 5 31.9 32.9 32.4 33.4 33.9 34.4 34.9 spectrum attenuation vs. frequency at different dither amplitudes ds1091l toc08 frequency (mhz) attenuation (db) 0% 1% 2% 4% 8db 11db 14db f out = 33.3mhz rbw = 120khz center dither 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 output rise time ds1091l toc06 time (ns) output (v) rise time = 1.02ns typical at 12pf load
detailed description the ds1091l is a clock generator that is capable of output frequencies from 130khz to 66.6mhz over the full automotive temperature range (-40? to +125?). the device also is capable of producing a spread- spectrum (dithered) square-wave output using four pin- selectable dither percentages. both center (ds1091la) and down (ds1091lb) dithering options are available. the device also features two selectable dither rates. the ds1091l is shipped from the factory programmed to a customer-specified frequency. spread spectrum the ds1091l has the ability to reduce radiated emis- sion peaks. the dither percentage is controlled by the state of the sel0 and sel1 pins. the output frequency can be dithered at 0%, ?%, ?%, and ?%, centered around the programmed frequency (for the ds1091lb this can be down dithered by 0%, -2%, -4%, and -8%). the two select pins sel0 and sel1 provide a means of selecting the dither magnitudes as follows: a triangle wave generator injects a control signal into the master oscillator to dither its output. the dither rate is a function of the output frequency, f out as well as the setting of the dr pin (see the equation below). figure 1 shows a plot of the output frequency versus time. where n is defined in table 2 as a function of output fre- quency. for example, for an output frequency of 27.0mhz, the dither rate would be 13.2khz for dr = 1 and 6.6khz for dr = 0. dither rate f out n = 2 ds1091l automotive temperature range spread-spectrum econoscillator _____________________________________________________________________ 5 block diagram factory-programmed master oscillator dither rate divider triangle wave generator (dither %) factory-programmed prescaler sel0 sel1 dr out f out v cc v cc gnd where f mosc is the master oscillator frequency. f mosc f dither f mosc ds1091l table 1. dither magnitude dither magnitude sel1 logic level sel0 logic level ds1091la ds1091lb 0 0 no dither no dither 0 1 ?% -2% 1 0 ?% -4% 1 1 ?% -8% table 2. value of n w.r.t. output frequency output frequency f out (mhz) n f out (min) f out (max) dr = logic level 1 dr = logic level 0 0.130 0.260 4 5 0.261 0.521 5 6 0.522 1.042 6 7 1.043 2.083 7 8 2.084 4.167 8 9 4.168 8.333 9 10 8.334 16.667 10 11 16.668 33.333 11 12 33.334 66.667 12 13
ds1091l automotive temperature range spread-spectrum econoscillator 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. 6 _____________________maxim integrated products, 120 san gabriel drive, sunnyvale, ca 94086 408-737-7600 2007 maxim integrated products is a registered trademark of maxim integrated products, inc. is a registered trademark of dallas semiconductor corporation. springer power-up upon the application of power, the ds1091l output is held in the low state until t pu has elapsed. this removes any possibility of erroneous output transitions during initial power-up. ds1091l frequency spreading profile as a function of dither % applications information power-supply decoupling to achieve best results, it is highly recommended that decoupling capacitors are used on the ic power-sup- ply pins. typical values of decoupling capacitors are 0.01? and 0.1?. use a high-quality, ceramic, sur- face-mount capacitor, and mount it as close as possi- ble to the v cc and gnd pins of the ic to minimize lead inductance. requesting custom frequencies contact technical support at www.maxim-ic.com/support for information/questions concerning custom frequencies. chip information transistor count: 4887 substrate connected to ground package information for the latest package outline information and land patterns, go to www.maxim-ic.com/packages . revision history pages changed at rev 1: 1, 6. time 1 dither freq programmed f out programmed f out - (2%, 4%, or 8% of f out ) dither amount (-2%, -4%, or -8%) if dither amount = 0% f out figure 1b. down dithered time 1 dither freq programmed f out + (1%, 2%, or 4% of f out ) programmed f out - (1%, 2%, or 4% of f out ) programmed f out dither amount ( 1%, 2%, or 4%) if dither amount = 0% f out figure 1a. center dithered package type package code document no. 8 ?ax u8+1 21-0036
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