general description the MAX31091 is a low-cost clock generator that is factory trimmed to output frequencies from 200khz to 66.6mhz with a nominal accuracy of 0.25%. the device can also produce a center-spread-spectrum output with pin-selectable dither magnitude and rate. assembled in an 8-pin max ? package, the MAX31091 is designed to operate with a 3.0v to 3.6v power supply over the auto - motive temperature range (-40c to +125c). applications automotive infotainment navigation advanced driver assistance system (adas) engine control unit (ecu) instrumentation features spread-spectrum clock output from 200khz to 66.6mhz -40c to +125c operating temperature range 1.75% accuracy across temperature factory trimmed center-dithered spread-spectrum output pin-selectable center-dither magnitude of 0%, 1%, 2%, or 4% pin-selectable dither rate 3.0v to 3.6v supply operation lead(pb)-free, 8-pin max package econoscillator is a trademark and max is a registered trademark of maxim integrated products, inc. for related parts and recommended products to use with this part, refer to: www.maximintegrated.com/MAX31091.related ordering information appears at end of data sheet. custom frequency options custom frequency options are available. see the ordering information or contact the factory by email at custom.oscillators@maximintegrated.com for more infor - mation. 19-7303; rev 0; 3/14 typical operating circuit 8 3 4 2 1 out dr v cc v cc f out decoupling capacitors 7 6 5 sel0 v cc n.c. n.c. sel1 gnd v cc MAX31091 MAX31091 automotive temperature range spread-spectrum econoscillator?
voltage range on v cc relative to ground ......... -0.5v to +4.0v voltage range on dr, sel0, sel1 relative to ground ............................... -0.5v to (v cc + 0.5v)* continuous power dissipation (t a = +70c) max (derate 4.5mw/c above +70c) ..................... 362mw operating temperature range ......................... -40c to +125c storage temperature range ............................ -55c to +125c lead temperature (soldering, 10s) ................................. +300c soldering temperature (reflow) ....................................... +260c * this voltage must not exceed 4.0v. max junction-to-ambient thermal resistance ( ja ) ........ 206c/w (note 1) recommended operating conditions (t a = -40 n c to +125 n c, unless otherwise noted.) dc electrical characteristics (v cc = +3.0v to +3.6v, t a = -40 n c to +125 n c, unless otherwise noted.) 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 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 = 0v -1 a supply current (active) i cc (note 2) 16 ma absolute maximum ratings note 1: package thermal resistances were obtained using the method described in jedec specification jesd51-7, using a four-layer board. for detailed information on package thermal considerations, refer to www.maximintegrated.com/thermal-tutorial . stresses beyond those listed under absolute 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 specifications is not implied. exposure to absolute maximum rating conditions for extended periods may affect device reliability. package thermal characteristics maxim integrated 2 www.maximintegrated.com MAX31091 automotive temperature range spread-spectrum econoscillator?
ac electrical characteristics (v cc = +3.0v to +3.6v, t a = -40 n c to +125 n c, unless otherwise noted.) typical operating characteristics (v cc = 3.3v, t a = +25c, unless otherwise noted.) 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 = +25c, f out = 66.6mhz, no dither. note 3: no dither. note 4: guaranteed by design. note 5: for aging characteristics, contact factory. parameter symbol conditions min typ max units output frequency range f out (note 3) 0.200 66.6 mhz output center frequency tolerance f out v cc = 3.3v, t a = +25 c -0.25 0 +0.25 % across t a and v cc = 3.3v -1.75 +1.75 0c to +70c and v cc = 3.3v -1.2 +1.2 power-up time t pu (note 4) 0.1 ms load capacitance c l 15 50 pf duty cycle < 33.3mhz (note 3) 50 % 33.3mhz (note 3) 40 60 jitter (rms), 50mhz 0.3 % 6.5 7 7.5 8 8.5 9 9.5 10 -40 10 60 110 i cc (ma) temperature ( c) supply current vs. temperature v cc = 3.3v v cc = 3.6v v cc = 3.0v f out = 66mhz toc01 -1.75 -1.25 -0.75 -0.25 0.25 0.75 1.25 1.75 -40 10 60 110 frequency variation (%) temperature ( c) frequency variation vs. temperature v cc = 3.3v no dither f out = 66mhz f out = 200khz toc02 -0.5 -0.4 -0.3 -0.2 -0.1 0 0.1 0.2 0.3 0.4 0.5 3 3.2 3.4 3.6 frequency variation (%) v cc (v) frequency variation vs. voltage no dither f out = 66mhz f out = 200khz toc03 maxim integrated 3 www.maximintegrated.com MAX31091 automotive temperature range spread-spectrum econoscillator?
typical operating characteristics (continued) (v cc = 3.3v, t a = +25c, unless otherwise noted.) 46 46.5 47 47.5 48 48.5 49 49.5 50 50.5 51 3 3.2 3.4 3.6 duty cycle (%) v cc (v) duty cycle vs. supply voltage no dither f out = 66mhz f out = 200khz toc04 44 45 46 47 48 49 50 51 52 -40 10 60 110 duty cycle (%) temperature ( c) duty cycle vs. temperature no dither f out = 66mhz f out = 200khz toc05 0 0.5 1 1.5 2 2.5 3 3.5 output (v) time (ns) output rise time rise time = 1.02ns typical at 12pf load toc06 0 0.5 1 1.5 2 2.5 3 3.5 output (v) time (ns) output fall time rise time = 1.12ns typical at 12pf load toc07 -35 -30 -25 -20 -15 -10 -5 0 5 31.9 32.9 33.9 attenuation (db) frequency (mhz) spectrum attenuation vs. frequency at differnet dither amplitudes f out = 33.3mhz rbw = 120khz center dither 0% 1% 2% 4% 8db 11db 14db toc08 maxim integrated 4 www.maximintegrated.com MAX31091 automotive temperature range spread-spectrum econoscillator?
pin name function 1 out spread-spectrum clock output 2 v cc supply voltage 3 gnd ground 4 sel1 spread-spectrum dither magnitude select inputs. selects dither magnitude (see table 1). 5 sel0 6, 7 n.c. no connection 8 dr spread-spectrum dither rate selector. selects dither rate (see table 2). 1 2 3 4 8 7 6 5 dr n.c. + n.c. sel0 sel1 gnd v cc out max top view MAX31091 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 f mosc is the master oscillator frequency. f mosc f dither f mosc MAX31091 block diagram pin confguration pin description maxim integrated g 5 www.maximintegrated.com MAX31091 automotive temperature range spread-spectrum econoscillator?
detailed description the MAX31091 clock generator is capable of output fre- quencies from 200khz to 66.6mhz over the full automo- tive temperature range (-40c to +125c). the device can also produce a spread-spectrum (dithered) square-wave output using four pin-selectable dither percentages. the device also features two selectable dither rates. the MAX31091 is shipped from the factory-programmed to a customer-specified frequency. spread spectrum the MAX31091 can reduce radiated emission peaks. the dither percentage is controlled by the state of the sel0 and sel1 pins. the output frequency can be dithered at 0%, 1%, 2%, and 4%, centered around the pro - grammed frequency. 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 set - ting of the dr pin (see the equation below). figure 1 shows a plot of the output frequency vs. time. out n f dither rate 2 = where n is defined in table 2 as a function of output frequency. 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. power-up upon the application of power, the MAX31091 output is held in the low state until t pu has elapsed. this removes any possibility of erroneous output transitions during initial power-up. figure 1a sel1 logic level sel0 logic level dither magnitude (%) MAX31091aua 0 0 no dither 0 1 q1 1 0 q2 1 1 q4 output frequency f out (mhz) n f out (min) f out (max) dr = logic level 1 dr = logic level 0 0.200 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 table 1. dither magnitude table 2. value of n w.r.t. output frequency 0)uhtxhqf6suhdglq3urohdvd)xqflrqrilkhu figure 1. center 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 maxim integrated g 6 www.maximintegrated.com MAX31091 automotive temperature range spread-spectrum econoscillator?
applications information power-supply decoupling to achieve best results, it is highly recommended that decoupling capacitors are used on the ic power-supply pins. typical values of decoupling capacitors are 0.01f and 0.1f. use a high-quality, ceramic, surface-mount capacitor, and mount it as close as possible to the v cc and gnd pins of the ic to minimize lead inductance. part temp range spread spectrum output frequency (mhz) pin-package MAX31091aua/v+033 -40c to +125c center 33.3 8 max MAX31091aua/v+t033 -40c to +125c center 33.3 8 max MAX31091aua/v+066 -40c to +125c center 66.6 8 max MAX31091aua/v+t066 -40c to +125c center 66.6 8 max MAX31091aua/v+172 -40c to +125c center 1.7 8 max MAX31091aua/v+t172 -40c to +125c center 1.7 8 max MAX31091aua/v+200 -40c to +125c center 0.20 8 max MAX31091aua/v+t200 -40c to +125c center 0.20 8 max MAX31091aua/v+330 -40c to +125c center 33.0 8 max MAX31091aua/v+t330 -40c to +125c center 33.0 8 max /v denotes an automotive qualified part. + denotes a lead(pb)-free/rohs-compliant package. t = tape and reel. ordering information package type package code outline no. land pattern no. 8 max u8+4 21-0036 90-0092 package information for the latest package outline information and land patterns (foot - prints), go to www.maximintegrated.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. chip information substrate connected to ground maxim integrated 7 www.maximintegrated.com MAX31091 automotive temperature range spread-spectrum econoscillator?
revision number revision date description pages changed 0 3/14 initial release revision history ? 2014 maxim integrated products, inc. 8 maxim integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a maxim integrated product. no circuit patent licenses are implied. maxim integrated reserves the right to change the circuitry and specifcations without notice at any time. the parametric values (min and max limits) shown in the electrical characteristics table are guaranteed. other parametric values quoted in this data sheet are provided for guidance. maxim integrated and the maxim integrated logo are trademarks of maxim integrated products, inc. MAX31091 automotive temperature range spread-spectrum econoscillator? for pricing, delivery, and ordering information, please contact maxim direct at 1-888-629-4642, or visit maxim integrateds website at www.maximintegrated.com.
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