asm3p2180a peak reducing emi solution ?2010 scillc. all rights reserved. p u blication order number: october 2010 C rev. 3 a sm3p2180/d features generates a 1x emi optimized clock output. input frequency: 6mhz - 10mhz 18mhz - 30mhz output frequency: 6mhz - 10mhz 18mhz - 30mhz two selectable down spread options. selectable frequency range. integrated loop filter components. operates with a 3.3v supply. cmos design. 8-pin soic packages. product description the asm3p2180a is a versatile spread spectrum fr equency modulator designed specifically for a wide range of clock frequencies. asm3p2180a reduces electromagnetic interference (emi) at the clock source, allowing system wide reduction of emi of down stream clock and data dependent signals. asm3p2180a allows significant system cost savings by reducing the number of circuit board layers, and shielding that are traditionally required to pass emi regulations. asm3p2180a modulates the output of a single pll in order to spread the bandwidth of a synthesized clock, thereby decreasing the peak amplitudes of its harmonics. this results in significantly lower system emi compared to the typical narrow band signal produced by oscillators and most clock generators. lowering emi by increasing a signals bandwidth is called spread spectrum clock generation. asm3p2180a uses the most efficient and optimized modulation profile approved by the fcc and is implemented by using a proprietary all-digital method. applications the asm3p2180a is targeted towards notebook lcd di splays, other displays using an lvds interface, pc peripheral devices and embedded systems. b lo ck diagram pll crystal oscillator clkin / xin xout clkout vdd gnd ss% fs modulation
asm3p2180a rev. 2 | page 2 of 6 | www.onsemi.com pin diagram p in description pin# pin name type description 1 clkin / xin i crystal connection or external reference clock input. 2 xout o connection for an external crystal. if using an external reference, this pin must be left unconnected. 3 gnd p ground to entire chip. 4 ss% i spread selection input. has an internal pull-up resistor. 5 clkout o modulated clock output. 6 vdd p power supply for the entire chip. 7 fs i frequency selection bit. this pin selects the frequency range of operation. ( refer to the frequency range selection table ). has an internal pull-up resistor. 8 nc - no connect. frequency range selection fs frequency range (mhz) 0 6-10 1 18-30 spread selection table ss% frequency (mhz) deviation (%) (typ) fs=0 fs=1 0 6 18 -2 8 24 -1.5 10 30 -1 1 6 18 -4 8 24 -3 10 30 -2 1 2 3 4 5 6 7 8 vdd nc clkout clkin / xin xout gnd ss% fs 3p2180a
asm3p2180a rev. 2 | page 3 of 6 | www.onsemi.com absolute maximum ratings symbol parameter rating unit vdd, v in voltage on any pin with respect to ground -0.5 to +4.6 v t stg storage temperature -65 to +125 c t s max. soldering temperature (10 sec) 260 c t j junction temperature 150 c t dv static discharge voltage (as per jedec std22- a114-b) 2 kv note: these are stress ratings only and are not implied for functional use. exposure to absolute maximum ratings for prolonged periods of time may affect device reliability. operating conditions parameter description min max unit vdd supply voltage 2.8 3.7 v t a operating temperature (ambient temperature) -40 +85 c c l load capacitance 15 pf c in input capacitance 7 pf dc electrical characteristics symbol parameter min typ max unit v il input low voltage gnd C 0.3 0.8 v v ih input high voltage 2.0 v dd + 0.3 v i il input low current (pull-up resistors on inputs ss%, fs) -27 a i ih input high current 18 a i xol x out output low current (@ 0.4v, v dd = 3.3v) 3 ma i xoh x out output high current (@2.5v, v dd = 3.3v) 4 ma v ol output low voltage (v dd = 3.3v, i ol = 4ma) 0.4 v v oh output high voltage (v dd = 3.3v, i oh = 4ma) 2.5 v i cc dynamic supply current normal mode (3.3v and 10pf loading) 10 15 25 ma i dd * static supply current standby mode 7 ma v dd operating voltage 2.8 3.3 3.7 v t on power up time (first locked clock cycle after power up) 0.18 ms z out clock output impedance 50 *clkin pin pulled to gnd
asm3p2180a rev. 2 | page 4 of 6 | www.onsemi.com ac electrical characteristics symbol parameter min typ max unit clkin input frequency fs=0 6 10 mhz fs=1 18 30 clkout output frequency fs=0 6 10 mhz fs=1 18 30 t lh * output rise time (measured at 0.8v to 2.0v) 1.2 1.3 1.4 ns t hl * output fall time (measured at 2.0v to 0.8v) 0.8 0.9 1.0 ns t jc jitter (cycle to cycle) 325 ps t d output duty cycle 45 50 55 % *t lh and t hl are measured into a capacitive load of 15pf t ypical test circuit +3.3v spread spectrum output (emi suppressed) xin gnd 0.1uf c load xout clkout vdd crystal c1 c2
asm3p2180a rev. 2 | page 5 of 6 | www.onsemi.com package information 8-pin soic package d e h d a1 a2 a q l c b e symbol dimensions inches millimeters min max min max a1 0.004 0.010 0.10 0.25 a 0.053 0.069 1.35 1.75 a2 0.049 0.059 1.25 1.50 b 0.012 0.020 0.31 0.51 c 0.007 0.010 0.18 0.25 d 0.193 bsc 4.90 bsc e 0.154 bsc 3.91 bsc e 0.050 bsc 1.27 bsc h 0.236 bsc 6.00 bsc l 0.016 0.050 0.41 1.27 0 8 0 8
asm3p2180a on semiconductor and are registered trademarks of semiconductor components industries, llc (scillc). scillc reserves the right to make changes without further notice to any products herein. scillc makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does scillc assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation special, consequential or incidental damages. typical parameters which may be provided in scillc data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. all operating parameters, including typicals must be validated for each customer application by customer's technical experts. scillc does not convey any license under its patent rights nor the rights of others. scillc products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications intended to support or sustain life, or for any other application in which the failure of the scillc product could create a situation where personal injury or death may occur. should buyer purchase or use scillc products for any such unintended or unauthorized application, buyer shall indemnify and hold scillc and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that scillc was negligent regarding the design or manufacture of the part. scillc is an equal opportunity/affirmative action employer. u.s patent pending; timing-safe and active bead are trademarks of pulsecore semiconductor, a wholly owned subsidiary of on semiconductor. this literature is subject to all applicable copyright laws and is not for resale in any manner. publication ordering information literature fulfillment: literature distribution center for on semiconductor p.o. box 5163, denver, colorado 80217 usa phone: 303-675-2175 or 800-344-3860 toll free usa/canada fax: 303-675-2176 or 800-344-3867 toll free usa/canada email: orderlit@onsemi.com n. american technical support: 800-282-9855 toll free usa/canada europe, middle east and africa technical support: phone: 421 33 790 2910 japan customer focus center phone: 81-3-5773-3850 on semiconductor website: www.onsemi.com order literature: http://www.onsemi.com/orderlit for additional information, please contact your local sales representative ordering codes part number marking package type temperature ASM3P2180AF-08ST act 8-pin soic, tube, pb free 0c to +70c asm3p2180af-08sr act 8-pin soic, tape and reel, pb free 0c to +70c a microdot placed at the end of last row of marking or just below the last row toward the center of package indicates pb-free.
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