pcs3p25811 and pcs3p25812 and pcs3p25814 spread spectrum clock generator ?2010 scillc. all rights reserved. publ i cation order number: novembe r 2010 C rev. 1.1 p cs3p25811/d fea tures generates a 1x (pcs3p25811), 2x (pcs3p25812) and 4x(pcs3p25814) low emi spread spectrum clock of the input frequency provides up to 15db of emi suppression input frequency: 4mhz - 32mhz output frequency: pcs3p25811: 4mhz - 32mhz pcs3p25812: 8mhz - 64mhz pcs3p25814: 16mhz - 128mhz selectable spread options: down spread and center spread low power dissipation: 3.3v: 20mw (typ) @ 6mhz 3.3v: 24mw (typ) @ 12mhz 3.3v: 30mw (typ) @ 24mhz low inherent cycle-to-cycle jitter supply voltage: 2.8v to 3.6v lvcmos input and output functional and pinout compatible to cypress cy25811, cy25812 and cy25814 8-pin soic, and 8l 2mmx2mm wdfn (tdfn) pack a ges produ ct description the pcs3p25811/12/14 devices are versatile spread spect rum frequency modulators designed specifically for a wide range of input clock frequencies from 4mhz to 32mhz. the pcs3p25811/12/14 reduce electromagnetic interference (emi) at the clock source, allowing system wide reduction of emi of down stream clock and data dependent signals. it allows significant system cost savings by reducing the number of circuit board layers, ferrite beads, shielding, and other passive components that are traditionally required to pass emi regulations. the pcs3p25811/12/14 can generate an emi reduced clock from crystal, ceramic resonator, or system clock. the pcs3p25811/12/14 modulate the output of a single pll in order to spread the bandwidth of a synthesized cock, and more importantly, decreases 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 frequency generators. lowering emi by increasing a signals bandwidth is called spread spectrum clock generation. the pcs3p25811/12/14 use the most efficient and optimized modulation profile approved by the fcc and is implemented in a proprietary all-digital method. the pcs3p25811/12/14 have 2 pins s0 and s1 to control the selection of center spread, down spread and no- spread functions. additionally there is a 3 level logic contol fsel, for selecting one of the three different frequency ranges within the operating frequency range. refer input/output frequency range selection table . the pcs3p25811/12/14 operate from a 2.8v to 3.6v supply and are available in 8 pin soic, and 8l 2mmx2mm wdfn packages. applications the pcs3p25811/12/14 are targeted towards emi manag ement in applications such as lcd panels, mfps, digital copiers, networking, pc peripheral devices, consumer electronics, and embedded controller systems.
pcs3p25811 and pcs3p25812 and pcs3p25814 rev. 1 | page 2 of 9 | www.onsemi.com block diagram pin configuration pin description pin# pin name type description 1 xin / clkin i crystal connection or external clock input. 2 vss p ground to entire chip. 3 s1 i digital 3 level logic input (1-m-0) used to select center, down and no spread options. (refer to frequency deviation selection table). default=m. 4 s0 i digital 3 level logic input (1-m-0) used to select center, down and no spread options. (refer to frequency deviation selection table). default=m. 5 modout o spread spectrum clock output. 6 fsel i frequency range select. digital 3 level logic input (1-m-0) used to select input clock frequency range (refer to input/output frequency range selection table ). default=m. 7 vdd p power supply for the entire chip (2.8v to 3.6v). 8 xout o crystal connection. if using an external reference, this pin must be left unconnected. modout 1 2 3 4 5 6 7 8 fsel xout xin / clkin vss s1 s0 vdd pcs3p25811 pcs3p25812 pcs3p25814 xin / clkin vss crystal oscillator frequency divider feedback divide r input decoder & modulation control phase detector loop filter vco output divider modout pll xout vdd fsel s1 s0
pcs3p25811 and pcs3p25812 and pcs3p25814 rev. 1 | page 3 of 9 | www.onsemi.com input/output frequency range selection table fsel (pin 6) part number modulation rate pcs3p25811 (1x) pcs3p25812 (2x) pcs3p25814 (4x) input (mhz) output (mhz) input (mhz) output (mhz) input (mhz) output (mhz) 0 4-8 4-8 4-8 8-16 4-8 16-32 input frequency / 128 1 8-16 8-16 8-16 16-32 8-16 32-64 input frequency / 256 m 16-32 16-32 16-32 32-64 16-32 64-128 input frequency / 512 output frequency deviation selection table clkin (mhz) fsel s1=0 s0=0 s1=0 s0=m s1=0 s0=1 s1=m s0=0 s1=1 s0=1 s1=1 s0=0 s1=m s0=1 s1=1 s0=m s1=m s0=m center center center center down down down down no spread 4-5 0 1.4 1.2 0.6 0.5 -3 -2.2 -1.9 -0.7 0 5-6 0 1.3 1.1 0.5 0.4 -2.7 -1.9 -1.7 -0.6 0 6-7 0 1.2 0.9 0.5 0.4 -2.5 -1.8 -1.5 -0.6 0 7-8 0 1.1 0.9 0.4 0.3 -2.3 -1.7 -1.4 -0.5 0 8-10 1 1.4 1.2 0.6 0.5 -3 -2.2 -1.9 -0.7 0 10-12 1 1.3 1.1 0.5 0.4 -2.7 -1.9 -1.7 -0.6 0 12-14 1 1.2 0.9 0.5 0.4 -2.5 -1.8 -1.5 -0.6 0 14-16 1 1.1 0.9 0.4 0.3 -2.3 -1.7 -1.4 -0.5 0 16-20 m 1.4 1.2 0.6 0.5 -3 -2.2 -1.9 -0.7 0 20-24 m 1.3 1.1 0.5 0.4 -2.7 -1.9 -1.7 -0.6 0 24-28 m 1.2 0.9 0.5 0.4 -2.5 -1.8 -1.5 -0.6 0 28-32 m 1.1 0.9 0.4 0.3 -2.3 -1.7 -1.4 -0.5 0 note: frequency deviation given in the table is for the input frequency range covering pcs3p25811/12 /14. 3 level digital logic s0, s1, and fsel digital inputs are designed to sense 3 di fferent logic levels designated as high 1, low 0 and middle m. with this 3-level digital input logic 9 different logic states can be detected. s0, s1 and fsel pins include an on chip 100k (50k/50k) resistor divider. no external application resistors are needed to implement the 3-level logic levels as shown below: logic control pins 1 fsel, s0, s1 to vdd m fsel, s0, s1 unconnected 0 fsel, s0, s1 to vss vss vdd
pcs3p25811 and pcs3p25812 and pcs3p25814 rev. 1 | page 4 of 9 | www.onsemi.com operating conditions symbol parameter min max unit vdd voltage on any pin with respect to vss 2.8 3.6 v t a operating temperature 0 +70 c c l load capacitance 15 pf c in input capacitance 7 pf 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 std 22- 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. dc electrical characteristics symbol parameter min typ max unit vdd supply voltage 2.8 3.3 3.6 v v il input low voltage (s0, s1, fsel inputs) commercial temp. 0 0.15v dd v industrial temp. 0 0.13 v dd v im input middle voltage (s0, s1, fsel inputs) 0.4vdd 0.60v dd v v ih input high voltage (s0, s1, fsel inputs) 0.85vdd v dd v v ol output low voltage (modout output) i ol = 4ma 0.4 v i ol = 10ma 1.2 v oh output high voltage (modout output) i oh = -4ma 2.4 v i oh = -6ma 2 c in input capacitance (xin and xout) 6 9 pf i dd dynamic supply current (unloaded output) commercial temp xin / clkin = 12mhz 8 ma xin / clkin = 24mhz 10 xin / clkin = 32mhz 13 industrial temp xin / clkin = 12mhz 10 ma xin / clkin = 24mhz 12 xin / clkin = 32mhz 15 i cc static supply current (xin / clkin pulled to vss) 0.5 ma note. the voltage on any input or i/o pin cannot exceed the power pin during power up. all parameters are specified at commercial and industrial temperature unless stated otherwise.
pcs3p25811 and pcs3p25812 and pcs3p25814 rev. 1 | page 5 of 9 | www.onsemi.com ac electrical characteristics symbol parameter min typ max unit f in input clock frequency for pcs3p25811/12/14 4 32 mhz f out modout clock frequency for pcs3p25811 4 32 mhz modout clock frequency for pcs3p25812 8 64 mhz modout clock frequency for pcs3p25814 16 128 mhz t lh 1, 2 modout rise time (measured from 20% to 80%) pcs3p25811/12/14 2 5 ns pcs3p25814 when fsel=m 1 2.2 t hl 1, 2 modout fall time (measured from 80% to 20%) pcs3p25811/12/14 2 4.4 ns pcs3p25814 when fsel=m 1 2.2 t dcin input clock duty cycle(xin / clkin) 40 60 % t dcout 1, 2 output clock duty cycle (modout) 40 60 % t jc 2 cy-cy jitter, for modout with spread on ( for commercial temperature ) pcs3p25811 4mhz 600 ps 8mhz 450 pcs3p25812 16mhz 400 32mhz 380 pcs3p25814 64mhz 380 128mhz 380 cy-cy jitter, for modout with spread on ( for industrial temperature ) pcs3p25811 pcs3p25812 pcs3p25814 clkin = 6mhz 500 ps clkin = 12mhz 400 clkin = 24mhz 380 t on 2 pll lock time (stable power supply, valid input clock to valid clock on modout) commercial temp. 2 ms industrial temp. 3 notes: 1.parameters are specified with 15pf loaded outputs. 2. parameter is guaranteed by design and characterization. not 100% tested in production.
pcs3p25811 and pcs3p25812 and pcs3p25814 rev. 1 | page 6 of 9 | www.onsemi.com application schematic ty pical crystal specifications fundamental at cut parallel resonant crystal nominal frequency 12mhz frequency tolerance 30 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 oscillations at overtone frequency of the fundamental frequency. ty pical 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. 1 2 6 7 fsel xout xin vss s0 s1 vdd pcs3p25811/12/14 4 3 8 5 y1 12mhz 0.1f c l c3 c l centre spread 0.5% 12mhz (pcs3p25811) 24mhz (pcs3p25812) 48mhz (pcs3p25814) vdd vdd vdd modout rx c l c l crystal r
pcs3p25811 and pcs3p25812 and pcs3p25814 rev. 1 | page 7 of 9 | 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 note: controlling dimensions are millimeters. soic: 0.074 grams unit weight.
pcs3p25811 and pcs3p25812 and pcs3p25814 rev. 1 | page 8 of 9 | www.onsemi.com 8l 2mmx2mm wdfn package symbol dimensions inches millimeters min max min max a 0.027 0.0315 0.70 0.80 a3 0.008 bsc 0.203 bsc b 0.008 0.012 0.20 0.30 d 0.077 0.080 1.95 2.05 e 0.077 0.080 1.95 2.05 e 0.020 bsc 0.50 bsc l 0.020 0.024 0.50 0.60
pcs3p25811 and pcs3p25812 and pcs3p25814 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 code part number marking package type temperature pcs3p25811ag08sr cgl 8-pin soic C tape & reel, green 0c to +70c p3p25812ag-08sr cil 8-pin soic C tape & reel, green 0c to +70c p3p25814ag-08sr ckl 8-pin soic C tape & reel, green 0c to +70c p3p25811ag-08cr cg 8l-wdfn (2mmx2mm) - tape & reel, green 0c to +70c p3p25812ag-08cr ci 8l-wdfn (2mmx2mm) - tape & reel, green 0c to +70c p3p25814ag-08cr ck 8l-wdfn (2mmx2mm) - tape & reel, green 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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