1 ps8848b 08/29/06 product features ? two high precision outputs: 27.000 mhz ssc clock output 27.000 mhz clock output ? four down-spread options: down-spread: C1% to C1.75% ? 14.318 mhz input (crystal or external reference) ? single 3.3v power supply ? packaging ( pb-free and green) : sotiny? 6-pin sot-23 (t) pi6c3420a 27 mhz spread spectrum clock synthesizer description the pi6c3420a is spread spectrum clock synthesizer targeted for video and graphics applications. the primary purpose of the spread spectrum is to minimize emi emissions. this device generates two 27.000 mhz outputs: a 27.000 mhz down spread spectrum output and a 27.000 mhz non-spread spectrum output . the pi6c3420a down spread range is from C1% to C1.75% when output frequency is at 27 mhz . spread spectrums are selectable through external pins. typically, the pi6c3420a uses a 14.318 mhz input crystal or frequency sou rce to generate a 27 mhz clock output . users can also get the adequate output clock setting from 15.1 mhz to 46.2 mhz by tuning the input frequency which can be set from 8 mhz to 24.5 mhz; the frequency multiplication factor is 1.886x. the pi6c3420a is housed i n a lead-free and green, sot-23, 6-pin sotiny package. the pi6c3420a belongs to pericom's clock and timing products. for other frequencies, features, functions or input/output not specifed, please contact pericom for information. block diagram pin confguration 27m 27m_ssc refin/x1 x2 s0 s1 clock synthesizer ? ?? ???????? ?????????? ??? ???? ? ?? ? ???? ? ???? ?? 06-0278
2 ps8848b 08/29/06 pi6c3420a 27 mhz spread spectrum clock synthesizer pin description pin name pin no i/o type description v dd 5 power power supply gnd 2 ground ground 27m 4 i/o 27 mhz clock output. 27m_ssc/s0 3 i/o s0 is activated during power on for logic state strapping, then switches to 27 mhz ssc clock output. x1/refin 1 i/o crystal or reference clock input x2/s1 6 i/o x2/s1 is a multiple function pin. s1 is active during power on selection of ssc spread then switches to crystal input. spread spectrum selection table ( v cc = 3.3v10%, ambient temperature +25, f out = 27 mhz) s0 s1 down spread(%) 0 0 C1 0 1 C1.25 1 0 C1.50 1 1 C1.75 06-0278
3 ps8848b 08/29/06 pi6c3420a 27 mhz spread spectrum clock synthesizer electrical specifcations maximum ratings (1) supply voltage to ground potential ......................................................... 5.5v all inputs and outputs ..................................................... -0.5v to v dd +0.5v ambient operating temperature ............................................ -1 0c to + 80 c storage temperature ............................................................. -65c to +150c operating temperature ............................................................... .. 0 to +70c, junction temperature ............................................................... ............. 150c soldering temperature ............................................................... ........... 260c dc characteristics (v dd = 3.3v 10%, ambient temperature 0c to +70 o c, f in = 14.318 mhz, f out = 27 mhz ) symbol parameter conditions min. typ. (1) max. unit v dd operating voltage +3.0 +3.3 +3.6 v v ih input high voltage 2 v v il input low voltage 0.8 v v oh output high voltage i oh = -4 ma 2.4 v v oh output high voltage i oh = -6 ma 2.0 v v ol output low voltage i ol = 4 ma 0.4 v v ol output low voltage i ol = 10 ma 1.2 v i dd supply current all outputs active with c l = 15pf load 55 ma z out_up nominal output impedance high side buffer 65 z out_low nominal output impedance low side buffer 40 c in input capacitance input pins 5 pf note: 1. typical conditions are at 3.3v for room temperature at 25c ac characteristics (v dd = 3.3v 10%, ambient temperature 0c to +70 o c) symbol parameter conditions min. typ. (1) max. unit f in refin input frequency refin clock input 8 14.318 24.5 mhz f out clock output frequency multiplication factor ( f in / f out = 1.885715) 15.1 27 46.2 mhz t rise output clock rise time from 0.4v to 2.4v, c l = 15 pf load 3 ns t fall output clock fall time from 2.4v to 0.4v, c l = 15 pf load 2.7 ns t j_short short term jitter cycle-to-cycle jitter ( f out = 27 mhz) 250 350 ps t dc input clock duty cycle refin/x1, measured @ v dd /2 20 50 80 % t dc output clock duty cycle measured @ v dd /2 ( f out = 27 mhz) 45 50 55 % ? ?/? actual mean frequency error versus target input frequency = 14.31818 mhz, output fre - quency = 27 mhz 0 ppm note: 1. typical conditions are at 3.3v for room temperature at 25c note: 1. stresses greater than those listed under maximum ratings may cause permanent damage to the device. this is a stress rating only and functional operation of the device at these or any other conditions above those indi - cated in the operational sections of this specifcation is not implied. exposure to absolute maximum rating conditions for extended periods may affect reliability. 06-0278
4 ps8848b 08/29/06 pi6c3420a 27 mhz spread spectrum clock synthesizer reference circuit for graphic chipset application (1-4) application information crystal load capacitors if a crystal is used with the device, the external trim capacitors c ltrim are used to adjust the effective capacitance to match the required crystal load capacitance. the c ltrim value can be derived from formula c ltrim = 2*c l C (cs + ci). typical c ltrim = 28pf when crystal load = 18pf, stray capacitance c s = 3pf and xtal pins capacitance = 5pf. c l trim c l trim xtal 6 1 notes: 1. pi6c3420a can accept a 14.31818mhz reference clock or crystal clock. 2. power supply pin decoupling capacitors should be placed as close as possible to vdd pin. via's at the vdd pin should be avoided. 3. spread select pin's (s0 and s1): pin 3 (27m_ssc/s0) and pin 6 (x2/s1) provide logic state strapping function. when strapping resistor connects to vdd, s0 and s1 are set to logic high. when strapping resistor connects to ground, s0 or s1 will set to logic low. 4. refer to "spread spectrum selection table", for more details on the strapping logic. strapping to high v dd v dd 5 2 3,6 0.1f 0.01f strapping to low v dd 5 2 3,6 0.1f 0.01f recommended crystal specifcation pericom recommends: srx7316-e crystal for optimum performance. parameter value units mode of oscillation, and cut fundamental at frequency 14.318 mhz frequency tolerance 20 ppm tempurature 30 ppm load cap 18 pf equivalent series resistance 40 ? drive to level 100 w aging stability 5 ppm/yr size = length x width x height 11.18(.440) x 4.65(.183) x 13.46(.530) mm(inch) note: pericom 's srx7316-e - 14.318 mhz series resonant crystal is recommended. 06-0278
5 ps8848b 08/29/06 pi6c3420a 27 mhz spread spectrum clock synthesizer ordering information (1-3) ordering code package code packagetype PI6C3420ATE t pb-free & green, 6-pin sot-23 notes: 1. thermal characteristics and package top marking information can be found at http://www .pericom.com/packaging/ 2. e = pb-free and green 3. x suffx = tape/reel pericom semiconductor corporation ? 1-800-435-2336 ? www.pericom.com ? description: 6-pin small outline transistor plastic package, sot-23 package code: t document control no. pd - 1912 revision: c date: 03/09/05 notes: 1) controlling dimensions in millimeters 2) ref: eiaj sc-74a 3) foot length is measured at fat portion of foot, reference to datum a pericom semiconductor corporation 3545 n. 1st street, san jose, ca 95134 1-800-435-2335 ? www.pericom.com 0.102 0.1 18 ? bsc 0.60 0.000 0.005 0.00 0.15 0.014 0.019 0.35 0.50 1.50 1.75 0.059 0.068 0.10 0.023 0.004 1.45 ? max. sea ting plane 0.057 0o - 10o 1.90 0.075 0.037 bsc 2.60 3.00 0.95 0.1 10 0.1 18 2.80 3.00 x.xx x.xx datum "a" denotes dimensions in millimeters 2 5 3 6 4 06-0278
|
