asm3p2111b peak emi reducing solution ?2010 scillc. all rights reserved. publication order number: january 2010 C rev. 1 asm3p2111/d features generates an emi optimized clock at the output. input frequency: 25mhz. frequency outputs: o 60mhz (unmodulated) o 2 x 48mhz (unmodulated) o 66.6mhz (modulated): -1.7% down spread modulation rate: 30khz. supply voltage range: 3.3v 0.3v. available in 8-pin soic package. rohs compliant product description the asm3p2111b is a versatile spread spectrum frequency modulator that reduces electromagnetic interference (emi) at the clock source. the asm3p21 11b allows significant system cost savings by reducing the number of circuit board layers and shielding that a re required to pass emi regulations. the asm3p2111b modulates the output of pll in order to spread the bandwidth of a synthesized clock, thereby decreasin g the peak amplitudes of its harmonics. this results in significantly lower system emi compared to the typi cal narrow band signal produced by oscillators and most clock generators. lowering emi by increasing a sign als bandwidth is called spread spectrum clock generatio n. applications asm3p2111b is targeted towards emi management for high speed digital applications such as pc peripher al devices, consumer electronics and embedded controll er systems. block diagram crystal oscillator 66.6mhz modulated xin / clkin xout v ss 48mhz_2 60mhz 48mhz_1 pll1 pll2 48mhz_1 v dd
asm3p2111b rev. 1 | page 2 of 7 | www.onsemi.com pin configuration pin description pin # pin name type description 1 xin / clkin i connection to crystal 2 xout o connection to crystal 3 v dd p power supply for the analog and digital blocks (+3. 3v) 4 60mhz o clock output-1 60mhz un-modulated 5 48mhz_2 o clock output-2 48mhz_2 un-modulated 6 48mhz_1 o clock output-3 48mhz_1 un-modulated 7 66.6mhz o clock output-4 66.6mhz modulated 8 v ss p ground to entire chip. connect to system ground 60mhz v ss xout xin/ clkin v dd 8 7 6 5 1 2 3 4 asm3p2111b 48mhz_2 48mhz_1 66.6mhz
asm3p2111b rev. 1 | page 3 of 7 | www.onsemi.com absolute maximum ratings symbol parameter rating unit v dd , 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 imp lied for functional use. exposure to absolute maxim um ratings for prolonged periods of time may affect device reliability. operating conditions symbol parameter min typ max unit v dd supply voltage 3 3.3 3.6 v f xin crystal resonator frequency 25 mhz t a operating temperature -40 +85 c c l output driver load capacitance 15 pf
asm3p2111b rev. 1 | page 4 of 7 | www.onsemi.com dc electrical characteristics ac electrical characteristics parameter symbol conditions / description min typ max unit rise time t r v o = 0.8v to 2.0v; c l = 15pf 300 800 900 ps fall time t f v o = 2.0v to 0.8v; c l = 15pf 360 800 900 ps clock duty cycle ratio of pulse width (as measured from rising edge to next falling edge at v dd /2) to one clock period 45 55 % note: 1. c l = 15pf, input clock frequency = 25mhz. parameter symbol conditions / description min typ max unit overall supply current, dynamic i dd v dd = 3.3v, f clk = 25mhz, c l = 15pf 41 48 62 ma supply current, static i ddl v dd = 3.3v, clock input = 0 20 25 35 ma all input pins high-level input voltage v ih v dd = 3.3v 2.0 v dd +0.3 v low-level input voltage v il v dd =3.3v v ss -0.3 0.8 v high-level input current i ih -1 1 a low-level input current (pull-up) i il -20 -36 -80 a high-level output source current i xoh v dd = v (xin) = 3.3v, v o = 0.4v 3 ma low-level output sink current i xol v dd = 3.3v, v (xin) = v o = 2.5v 3 ma clock outputs high-level output source current i oh v o = 2.5v -20 ma low-level output sink current i ol v o = 0.4v 23 ma output impedance z oh v o = 0.5 v dd ; output driving high 29 w z ol v o = 0.5 v dd ; output driving low 27
asm3p2111b rev. 1 | page 5 of 7 | www.onsemi.com typical crystal specifications fundamental at cut parallel resonant crystal nominal frequency 25mhz frequency tolerance 50 ppm or better at 25c operating temperature range -25c to +85c storage temperature -40c to +85c load capacitance(c p ) 18pf shunt capacitance 7pf maximum esr 25 w note: note: c l is load capacitance and rx is used to prevent osci llations at overtone frequency of the fundamental f requency. typical crystal interface circuit c l = 2*(c p C c s ), where c p = load capacitance of crystal c s = stray capacitance due to c in, pcb, trace etc. rx c l c l crystal r
asm3p2111b rev. 1 | page 6 of 7 | www.onsemi.com package information 8-lead (150-mil) 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
asm3p2111b note: this product utilizes us patent #6,646,463 im pedance emulator patent issued to pulsecore semicon ductor, dated 11-11-2003. on semiconductor and are registered trademarks of semiconductor componen ts industries, llc (scillc). scillc reserves the ri ght to make changes without further notice to any products herein. sci llc makes no warranty, representation or guarantee regarding the suitability of its products for any p articular purpose, nor does scillc assume any liability arisi ng out of the application or use of any product or circuit, and specifically disclaims any and all lia bility, 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 applica tions and actual performance may vary over time. al l operating parameters, including typicals must b e validated for each customer application by customer 's technical experts. scillc does not convey any l icense under its patent rights nor the rights of ot hers. scillc products are not designed, intended, or auth orized for use as components in systems intended fo r surgical implant into the body, or other applicat ions intended to support or sustain life, or for any oth er application in which the failure of the scillc p roduct could create a situation where personal inju ry or death may occur. should buyer purchase or use scillc pro ducts for any such unintended or unauthorized appli cation, 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 fe es arising out of, directly or indirectly, any claim of person al injury or death associated with such unintended or unauthorized use, even if such claim alleges tha t scillc was negligent regarding the design or manufacture o f the part. scillc is an equal opportunity/affirmat ive action employer. u.s patent pending; timing-sa fe and active bead are trademarks of pulsecore semicon ductor, a wholly owned subsidiary of on semiconduct or. 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 configuration temperature range ASM3P2111BG-08SR aei 8-pin soic tape & reel, green 0c to +70c a microdot placed at the end of last row of marki ng or just below the last row toward the center of package indicates pb-free licensed under us patent #5,488,627, #6,646,463 and #5,631,920.
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