february 2007 ASM3P2531A rev 1.4 notice: the information in this document is subject to change without notice. pulsecore semiconductor corporation 1715 s. bascom ave suite 200, campbell, ca 95008 ? tel: 408-879-9077 ? fax: 408-879-9018 www. p ulsecoresemi.com low frequency emi reduction features ? fcc approved method of emi attenuation. ? generates a low emi spread spectrum of the input clock frequency. ? optimized for input frequency range between 27mhz ? 55mhz. ? internal loop filter minimizes external components and board space. ? frequency deviation: 1.7%. ? low inherent cycle-to-cycle jitter. ? 3.3 v 0.3v oper ating voltage. ? ultra low power cmos design:3.0 ma @ 3.3 v. ? supports notebook vga and other lcd timing controller applications. ? available in 8-pin soic and tssop packages. product description the ASM3P2531A is a versatile spread spectrum frequency modulator designed specifically for a wide range of clock frequencies. it reduces electromagnetic interference (emi) at the clock source allowing system- wide reduction of emi of downstream clock and data dependent signals. it allows significant system cost savings by reducing the number of circuit board layers and shielding traditionally required to pass emi regulations. the ASM3P2531A 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 result in significantly lower system emi compared to the typical narrow band signal produced by oscillators and most clock generators. lowering emi by increasing a signal?s bandwidth is called spread spectrum clock generation. the ASM3P2531A uses the most efficient and optimized modulation profile approved by the fcc and is implemented by using a proprietary all-digital method. applications the ASM3P2531A is targeted toward the notebook vga chip and other displays using an lvds interface, pc peripheral devices, and embedded systems. block diagram clkin crystal oscillator frequency divider feedback divider modulation phase detector loop filter vco output divider modout pll v dd v ss stop
february 2007 ASM3P2531A rev 1.4 low frequency emi reduction 2 of 8 notice: the information in this document is subject to change without notice. stop pin configuration (8-pin soic and tssop packages) spread range selection, v dd = 3.3 v clkin frequency spreading range modulation rate 27mhz ? 55mhz 1.7% (clkin/1280) khz pin description pin# pin name type description 1 clkin i external reference frequency input. 2 v dd p power supply for the entire chip. 3 v ss p ground to entire chip. 4 modout o spread spectrum clock output or re ference output.( refer standby mode selection.) 5 stop i active low signal. when high, enables m odout and when low, modout would be low. 6 nc - no connect. 7 nc - no connect. 8 nc - no connect. 8 7 6 5 4 3 2 1 clkin v dd modout v ss nc nc nc ASM3P2531A
february 2007 ASM3P2531A rev 1.4 low frequency emi reduction 3 of 8 notice: the information in this document is subject to change without notice. schematic for a typical application 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 a operating temperature -40 to +85 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. 1 2 3 4 5 6 7 8 clkin v dd v ss modout stop nc nc nc emi reduced clock output 27mhz ? 55mhz a sm3p2531 a in pu t c l oc k 27mhz ? 55 mhz use either pull-up or pull-down resistors with 0 ? vdd fb gnd 0.1uf fb : optional ferrite bead vdd 0 ? 0 ?
february 2007 ASM3P2531A rev 1.4 low frequency emi reduction 4 of 8 notice: the information in this document is subject to change without notice. dc electrical characteristics symbol parameter min typ max unit v il input low voltage v ss - 0.3 0.8 v v ih input high voltage 2.0 v dd + 0.3 v i il input low current -35 a i ih input high current 35 a v ol output low voltage v dd = 3.3v, i ol = 6 ma 0.4 v v oh output high voltage v dd = 3.3v, i oh = 15 ma 2.5 v i dd static supply current standby mode 3.0 ma i cc dynamic supply current 3.3v and 15pf loading 10 14 ma v dd operating volta ge 3.0 3.3 3.6 v t on power-up time (first locked cycle after power up) 0.18 ms z out clock output impedance 50 ? ac electrical characteristics symbol parameter min typ max unit f in input frequency 27 55 mhz f out output frequency 27 55 mhz t lh 1 output rise time measured from 0.8 v to 2.0 v 0.4 0.6 1.2 ns t hl 1 output fall time measured from 2.0 v to 0.8 v 0.4 0.6 1.2 ns t jc jitter (cycle to cycle) 360 ps t d output duty cycle 45 50 55 % note 1: t lh and t hl are measured into a capacitive load of 15pf
february 2007 ASM3P2531A rev 1.4 low frequency emi reduction 5 of 8 notice: the information in this document is subject to change without notice. package information 8-lead (150-mil) soic package d e h d a1 a2 a l c b e dimensions inches millimeters symbol 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
february 2007 ASM3P2531A rev 1.4 low frequency emi reduction 6 of 8 notice: the information in this document is subject to change without notice. e h a a1 a2 d b c l e 8-lead thin shrunk small outline package (4.40-mm body) dimensions inches millimeters symbol min max min max a 0.043 1.10 a1 0.002 0.006 0.05 0.15 a2 0.033 0.037 0.85 0.95 b 0.008 0.012 0.19 0.30 c 0.004 0.008 0.09 0.20 d 0.114 0.122 2.90 3.10 e 0.169 0.177 4.30 4.50 e 0.026 bsc 0.65 bsc h 0.252 bsc 6.40 bsc l 0.020 0.028 0.50 0.70 0 8 0 8
february 2007 ASM3P2531A rev 1.4 low frequency emi reduction 7 of 8 notice: the information in this document is subject to change without notice. ordering information ordering code marking package type operating range ASM3P2531Af-08st 3p2531af 8-pin 150mil soic ?tube, pb free commercial ASM3P2531Af-08sr 3p2531af 8-pin 150-mil soic -tape & reel, pb free commercial asm3i2531af-08st 3p2531af 8-pin 150mil soic -tube, pb free industrial asm3i2531af-08sr 3p2531af 8-pin 150-mil soic -tape & reel, pb free industrial ASM3P2531Af-08tt 3p2531af 8-pin 4.4mm tssop -tube, pb free commercial ASM3P2531Af-08tr 3p2531af 8-pin 4.4mm tssop -tape & reel, pb free commercial asm3i2531af-08tt 3p2531af 8-pin 4.4mm tssop -tube, pb free industrial asm3i2531af-08tr 3p2531af 8-pin 4.4mm tssop - tape & reel, pb free industrial ASM3P2531Ag-08st 3p2531ag 8-pin 150mil soic ?tube, green commercial ASM3P2531Ag-08sr 3p2531ag 8-pin 150-mil soic -tape & reel, green commercial asm3i2531ag-08st 3p2531ag 8-pin 150mil soic -tube, green industrial asm3i2531ag-08sr 3p2531ag 8-pin 150-mil soic -tape & reel, green industrial ASM3P2531Ag-08tt 3p2531ag 8-pin 4.4mm tssop -tube, green commercial ASM3P2531Ag-08tr 3p2531ag 8-pin 4.4mm tssop -tape & reel, green commercial asm3i2531ag-08tt 3p2531ag 8-pin 4.4mm tssop -t ube, green industrial asm3i2531ag-08tr 3p2531ag 8-pin 4.4mm tssop - tape & reel, green industrial device ordering information ASM3P2531Af-08tr licensed under us patent #5,488 ,627, #6,646,463 and #5,631,920. o = sot u = msop s = soic e = tqfp t = tssop l = lqfp a = ssop u = msop v = tvsop p = pdip b = bga d = qsop q = qfn x = sc - 70 device pin count x= automotive i= industrial p or n/c = commercial (-40c to +125c) (-40c to +85c) (0c to +70c) 1 = reserved 6 = power management 2 = non pll based 7 = power management 3 = emi reduction 8 = power management 4 = ddr support products 9 = hi performance 5 = std zero dela y buffe r 0 = reserved pulsecore semiconductor mixed signal product device number f = lead free and rohs compliant part g = green package, lead free, and rohs r = tape & reel, t = tube or tray
february 2007 ASM3P2531A rev 1.4 low frequency emi reduction 8 of 8 notice: the information in this document is subject to change without notice. ? copyright 2007 pulsecore semiconductor corporation. all rights reserved. our logo and name are trademarks or registered trademarks of pulsecore semiconductor. all ot her brand and product names may be the trademarks of their respective companies. pulsecore reserves the right to make changes to this document and its products at any time without notice. pulsecore assumes no responsibility for any errors t hat may appear in this document. the data contained herein represents pulsecore?s best data and/or estimates at the time of issuance. pulsecore reserves the right to change or correct this data at any time, without notice. if the product descri bed herein is under development, significant changes to these specifications are possible. the information in this product data sheet is intended to be general descriptive information for potential customers and users, and is not in tended to operate as, or provide, any guarantee or warrantee to any user or customer. pulsecore does not assume any responsibility or liability arising out of the app lication or use of any product described herein, and disclaims any express or implied warrant ies related to the sale and/or use of pulsecore products including liability or warranties related to fitness for a particular purpose, mercha ntability, or infringement of any intellec tual property rights, except as express agreed to in pulsecore? s terms and conditions of sale (which are available from pulsecore). all sales of pulsecore products are made exclusiv ely according to pulsecore?s terms and conditions of sale. the purchase of products from pulsecore does not convey a license under any patent rights, copyrights; mask works rights, trademarks, or any other intellect ual property rights of pulsecore or third partie s. pulsecore does not authorize its products for use as critical components in life-supp orting systems where a malfunction or failu re may reasonably be expected to result in significant injury to the user, and the inclusion of pulsec ore products in such life-supporting systems implies that the manufacturer assumes all risk of such use and agrees to inde mnify pulsecore against all claims arising from such use. pulsecore semiconductor corporation 1715 s. bascom ave suite 200 campbell, ca 95008 tel: 408-879-9077 fax: 408-879-9018 www.pulsecoresemi.com copyright ? pulsecore semiconductor all rights reserved part number: ASM3P2531A document version: v1.4 note: this product utilizes us patent # 6,646,463 impedance emulator patent issued to pulsecore semiconductor, dated 11-11-2003
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