october 2002 this document contains information on a preproduction product. specifications and information herein are subject to change with out notice. 10.29.02 t73227 27 mhz vcxo clock generator ic iso9001 1.0 features ? one-chip tunable voltage controlled crystal oscillator (vcxo) allows precise system frequency tuning ? 3.3v operation ? 8 pin soic and msop packages ? uses inexpensive 20pf pullable crystals with no external capacitors required. ? 12ma drive capability at ttl levels 2.0 applications ? set-top boxes ? mpeg video clock source ? oscillator replacement 3.0 description the t73227 is a single-chip, low-jitter voltage-controlled- crystal-oscillator. the device accepts a 27 mhz, 20 pf crystal, and produces a low jitter output at the same fre- quency. a 0 to 3.0v control signal is used to fine tune the output clock frequency in the 100ppm range. this finds use in systems that have frequency matching require- ments, such as digital satellite receivers. figure 1: block diagram clk vdd2 vdd1 x2 load cap control output buffer load caps 27 mhz pullable crystal vin x1 gnd1 gnd2 oscillator
october 2002 2 10.29.02 iso9001 t73227 27 mhz vcxo clock generator ic table 1: pin descriptions pin type name description 1 xi x1 crystal connection. connect to a 27 mhz pullable crystal 2 p vdd1 core v dd . connect to 3.3v 3 i vin voltage input to vcxo. zero to 3.3v signal controls the frequency of the vcxo. 4 p gnd2 connect to ground. 5 o clk clock output 6 p vdd2 pad driver v dd . connect to 3.3v 7 p gnd1 connect to ground. 8 xi x2 crystal connection. connect to a 27 mhz pullable crystal. legend: i = input o = output p = power supply connection xi = crystal connections. 1 2 3 4 8 7 6 5 x1 v dd1 vin gnd2 x2 gnd1 v dd2 clk 8-pin soic/msop
october 2002 3 10.29.02 iso9001 t73227 27 mhz vcxo clock generator ic 4.0 functional block description the vcxo provides a tunable, low-jitter frequency reference. loading capacitance for the crystal is internal to the t73227. no external components (other than the crystal resonator itself) are required for operation of the vcxo. tuning of the vcxo frequency is accomplished by varying the voltage on vin (pin 3). the oscillator operates the crystal resonator in the parallel-resonant mode. crystal warping, or the ?pulling? of the crys- tal oscillation frequency, is accomplished by altering the effective load capacitance presented to the crystal by the os- cillator circuit. the actual amount that changing the load capacitance alters the oscillator frequency will be dependent on the characteristics of the crystal as well as the oscillator circuit itself. specifically, the motional capacitance of the crystal (usually referred to by crystal manufacturers as c 1 ), the static ca- pacitance of the crystal (c 0 ), and the load capacitance (c l ) of the oscillator determine the ?warping? or ?pulling? capability of the crystal in the oscillator circuit. a simple formula to obtain the warping capability of a crystal oscil- lator is: () ()() c c c c c c c ppm f l l l l 1 0 2 0 6 1 2 1 2 10 ) ( + + ? = ? where c l1 and c l2 are the two extremes of the applied load capacitance. example: a crystal with the following parameters is used. with c 1 = 0.025pf, c 0 = 6pf, c l1 = 10pf, and c l2 = 20pf, the tuning range is () ()() ppm . f 300 10 6 20 6 2 10 6 10 20 025 0 = + + ? = ? . 5.0 electrical specifications table 2: absolute maximum ratings stresses above those listed under absolute maximum ratings may cause permanent damage to the device. these conditions represent a stress rating only, and functional operation of the device at these or any other conditions above the operational limits noted in this specification is not implied. exposure to maximum rati ng conditions for extended conditions may affect device performance, functionality, and reliab ility. parameter symbol min. max. units supply voltage (v ss = ground) v dd v ss -0.5 5 v input voltage, dc v i v ss -0.5 v dd +0.5 v output voltage, dc v o v ss -0.5 v dd +0.5 v input clamp current, dc (v i < 0 or v i > v dd ) i ik -25 25 ma output clamp current, dc (v i < 0 or v i > v dd ) i ok -50 50 ma storage temperature range (non-condensing) t s -65 150 c ambient temperature range, under bias t a -55 125 c junction temperature t j 125 c lead temperature (soldering, 10s) 260 c input static discharge voltage protection 2 kv t73227 typical vcxo deviation vs. vin -150 -100 -50 0 50 100 150 0.1 0.4 0.7 0.9 1.2 1.5 1.8 2.0 2.3 2.5 2.7 vin deviation from 27 mhz ppm
october 2002 4 10.29.02 iso9001 t73227 27 mhz vcxo clock generator ic table 3: operating conditions parameter symbol conditions/description min. typ. max. units core supply voltage (v dd ) v dd 3.15 3.3 3.45 v vcxo control voltage, v in v in 0 v dd v ambient operating temperature range t a 0 70 c crystal resonator frequency f xtal fundamental mode 20 27 30 mhz crystal load capacitance c l(xtal) at cut 20 pf table 4: dc electrical specifications unless otherwise stated, v dd = 3.15v to 3.45v , no load on any output, and ambient temperature range t a = 0c to 70c. parameter symbol conditions/description min. typ. max. units overall supply current, dynamic, with no load i dd f xtal = 27mhz 25 ma output high voltage v oh i oh = -12ma 2.4 v output low voltage v ol i ol = 12ma 0.4 v voltage controlled crystal oscillator - vdd=3.3v crystal loading capacitance c l(xtal) as seen by a crystal connected to xin and xout (@ v xtune = 1.65v) 20 pf crystal gamma c o /c 1 240 vcxo tuning range f xtal = 27mhz; c l(xtal) = 20pf; gamma = 240 250 ppm vcxo tuning characteristic note: positive ? f for positive ? v 75 ppm/v crystal esr 50 ? table 5: ac timing specifications unless otherwise stated, v dd = 3.15v to 3.45v, no load on any output, and ambient temperature range t a = 0c to 70c. parameters denoted with an asterisk ( * ) represent nominal characterization data and are not production tested to any specific limits. parameter symbol conditions/description min. typ. max. units clock output (clk) duty cycle * ratio of high pulse width (as measured from rising edge to next falling edge at v dd /2) to one clock period 40 60 % jitter, period (peak-peak) * t j( ? p) from rising edge to next rising edge at v dd /2, c l = 10pf 150 ps rise time * t r measured 0.8v to 2.0v, c l = 10pf 1.5 ns fall time * t f measured 2.0v to 0.8v; c l = 10pf 1.5 ns
october 2002 5 10.29.02 iso9001 t73227 27 mhz vcxo clock generator ic phase noise, dbc/hz phase noise vs. frequency offset frequency offset from 27mhz 100 1k 10k 100k 1m - 50 - 70 - 90 - 110 - 130 - 150 6.0 ordering information ordering part number package type shipping configuration t73227-s08 8-pin soic tubes T73227-S08-TNR 8-pin soic tape and reel t73227-m08 8-pin msop tubes t73227-m08-tnr 8-pin msop tape and reel t73227-die die waffle-pack tlsi reserves the right to make changes to its products or to discontinue any product or service without notice, and advise cus tomers to obtain the latest version of relevant information to verify, before placing orders, that information being relied on is current and complete. all products are sold subject to the terms and conditions of sale supplied at the time of order acknowledgment, includ- ing those pertaining to warranty, patent infringement, and limitation of liab ility. tlsi warrants performance of its semiconductor products to the specifications applicable at the time of sale in accordance with tlsi?s standard warranty. testing and other quality control techniques are utilized to the extent tlsi deems necessary to support this warranty. specific testing of all parameters of each device is not necessarily performed, exce pt those mandated by government requirements. customers are responsible for their applications using tlsi devices. information furnished by tlsi is believed to be accurate and reliable. however, no responsib ility is assumed by tlsi for its use, nor for any infringements of patents or other rights of third parties which may result from its use. no license is granted by implication or otherwise under any patent rights of tlsi. tlsi and s ilicon driven are tr ademarks of tlsi, inc. all other trademarks are the property of their respective owners. tlsi incorporated, 770 park avenue, huntington ny 11743 ? ? ? ? (631) 755-7005 ? ? ? ? fax 631-755-7626 ? ? ? ? www.tlsi.com
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