datasheet vcxo plus audio clock for stb mk3722 idt? vcxo plus audio clock for stb 1 mk3722 rev g 051310 description the mk3722 is a low cost, low jitter, high performance vcxo and pll clock synthesizer designed to replace expensive discrete vcxos and multipliers. the patented on-chip voltage controlled cryst al oscillator accepts a 0 to 3.3 v input voltage to cause the output clocks to vary by 115 ppm. using idt?s analog/digital phase-locked loop (pll) techniques, the device uses an inexpensive 27 mhz pullable crystal input to produce a reference output and a selectable audio clock. idt manufactures the largest variety of vcxo based timing devices for all applications. consult idt to eliminate vcxos, crystals, and osc illators from your board. the frequency of the on-chip vcxo is adjusted by an external control voltage connected to vin. because vin is a high impedance input, it can be driven directly from an pwm rc integrator circuit. features ? packaged in 16-pin tssop ? pb (lead) free package ? replaces a vcxo and oscillator ? operating voltage of 3.3v ? provides output of 27 mhz plus audio clock ? uses an inexpensive 27 mhz pullable crystal ? on-chip patented vcxo with pull range of 230 ppm (minimum) ? vcxo tuning voltage of 0 to 3.3 v ? advanced, low power, sub-micron cmos process block diagram x1 x2 voltage controlled crystal oscillator vin 27 mhz pullable crystal pll/clock synthesis circuitry aclk 27mhz s2:s0 vdd gnd 3 3 3 pdts
mk3722 vcxo plus audio clock fo r stb vcxo and synthesizer idt? vcxo plus audio clock for stb 2 mk3722 rev g 051310 pin assignment pin descriptions audio clock select table 12 1 11 2 10 3 9 x2 4 x1 5 vdd 6 nc 7 vdd 8 vin vdd s0 27m gnd gnd s2 gnd aclk 16 15 14 13 pdts s1 16 pin 4.40mm body, 0.65mm pitch tssop s2 s1 s0 aclk (mhz) 000 8.192 0 0 1 11.2896 0 1 0 12.288 0 1 1 16.9344 1 0 0 18.432 1 0 1 16.384 1 1 0 22.5792 1 1 1 24.576 pin number pin name pin type pin description 1 x2 output crystal connection. conn ect to a 27mhz fundamental mode pullable crystal. 2 x1 input crystal connection. conn ect to a 27mhz fundamental mode pullable crystal. 3 vdd power connect to +3.3 v. 4 vdd power connect to +3.3 v. 5 vin input voltage input to vcxo. zero to 3.3v signal which controls the vcxo frequency. 6 gnd power connect to ground. 7 gnd power connect to ground. 8pdts power power down tri-state. this pin powers down entire chip and tri-states the outputs when low. internal pull-up. 9 s2 input select input s2. selects aclk per table above. internal pull-up. 10 aclk output audio clock output per table above. 11 gnd power connect to ground. 12 27m output 27mhz reference clock output. 13 s0 input select input s0. selects aclk per table above. internal pull-up. 14 vdd power connect to +3.3v. 15 nc -- no connect. do not connect anything to this pin. 16 s1 input select input s1. selects aclk per table above. internal pull-up.
mk3722 vcxo plus audio clock fo r stb vcxo and synthesizer idt? vcxo plus audio clock for stb 3 mk3722 rev g 051310 external component selection the mk3722 requires a minimum number of external components for proper operation. decoupling capacitors decoupling capacitors of 0.01 f should be connected between vdd and gnd on pins 3 and 4, pins 6 and 7, and pins 11 and 14 as close to the mk3722 as possible. for optimum device performance, the decoupling capacitors should be mounted on the component side of the pcb. avoid the use of vias in the decoupling circuit. series termination resistor when the pcb traces between the clock outputs and the loads are over 1 inch, series termination should be used. to series terminate a 50 ? trace (a commonly used trace impedance) place a 33 ? resistor in series with the clock line, as close to the clock output pin as possible. the nominal impedance of the clock output is 20 ? . quartz crystal the mk3722 vcxo function consists of the external crystal and the integrated vcxo oscilla tor circuit. to assure the best system performance (frequency pull range) and reliability, a crystal device meeting idt? recommended parameters must be used, and the layout guidelines discussed in the following section must be followed. see application note man05 for a full list of crystal parameters. the frequency of oscilla tion of a quartz crystal is determined by its ?cut? and by the load capacitors connected to it. the mk3722 incorporates on-chip variable load capacitors that ?pull? (change) the frequency of the crystal. the crystal specified for use with the mk3722 is designed to have zero frequency error when the total of on-chip + stray capacitance is 14pf. the external crystal must be connected as close to the chip as possible and should be on the same side of the pcb as the mk3722. there should be no via?s between the crystal pins and the x1 and x2 device pins. there should be no signal traces underneath or close to the crystal. crystal tuning load capacitors the crystal traces should include pads for small fixed capacitors, one between x1 and ground, and another between x2 and ground. stuffing of these capacitors on the pcb is optional. the need for these capacitors is determined at system prototype evaluation, and is influenced by the particular crystal used (manufacture and frequency) and by pcb layout. the typical required capacitor value is 1 to 4 pf. the procedure for determining the value of these capacitors can be found in application note man05.
mk3722 vcxo plus audio clock fo r stb vcxo and synthesizer idt? vcxo plus audio clock for stb 4 mk3722 rev g 051310 absolute maximum ratings stresses above the ratings listed below can cause perm anent damage to the mk3722. these ratings, which are standard values for idt commercially rated parts, are stress ratings only. functional operation of the device at these or any other conditions above those indicated in the operational sections of the specifications is not implied. exposure to absolute maximum rating conditions for exte nded periods can affect product reliability. electrical parameters are guaranteed only over the recommended operating temperature range. recommended operation conditions dc electrical characteristics vdd=3.3 v 5% , ambient temperature 0 to +70 c, unless stated otherwise item rating supply voltage, vdd 7 v all inputs and outputs -0.5 v to vdd+0.5 v ambient operating temperature 0 to +70 c storage temperature -65 to +150 c soldering temperature 260 c parameter min. typ. max. units ambient operating temperature 0 +70 c power supply voltage (measured in respect to gnd) +3.15 +3.45 v reference crystal parameters refer to page 3 parameter symbol conditions min. typ. max. units operating voltage vdd 3.15 3.45 v output high voltage v oh i oh = -12 ma 2.4 v output low voltage v ol i ol = 12 ma 0.4 v output high voltage (cmos level) v oh i oh = -4 ma vdd-0.4 v input high voltage (s1:s0) v ih 2.0 v input high voltage (s2) v ih 2.5 v input low voltage (s1:s0) v il 0.8 v input low voltage (s2) v il 0.5 v operating supply curr ent idd no load, 2 outputs 11 ma short circuit current i os 50 ma vin, vcxo control voltage v ia 03.3v on chip pull-up resistor, inputs r pu s0, s1, s2 150 k ? input capacitance c in s0, s1, s2 5 pf nominal output impedance z out 20 ?
mk3722 vcxo plus audio clock fo r stb vcxo and synthesizer idt? vcxo plus audio clock for stb 5 mk3722 rev g 051310 ac electrical characteristics vdd = 3.3 v 5% , ambient temperature 0 to +70 c, unless stated otherwise note 1: external crystal device must conform with pullable crystal specifications listed on page 3. thermal characteristics parameter symbol conditions min. typ. max. units crystal pullability f p 0v< vin < 3.3 v, note 1 + 100 ppm vcxo gain vin = vdd/2 + 1 v, note 1 80 ppm/v output rise time t or 0.8 to 2.0 v, c l =15 pf 0.75 1.5 ns output fall time t of 2.0 to 0.8 v, c l =15 pf 0.75 1.5 ns output clock duty cycle t d measured at 1.65 v, c l =15 pf 40 50 60 % maximum output jitter, short term t j c l =15 pf + 150 ps parameter symbol conditions min. typ. max. units thermal resistance junction to ambient ja still air 78 c/w ja 1 m/s air flow 70 c/w ja 3 m/s air flow 68 c/w thermal resistance junction to case jc 37 c/w
mk3722 vcxo plus audio clock fo r stb vcxo and synthesizer idt? vcxo plus audio clock for stb 6 mk3722 rev g 051310 package outline and package dimensions (16-pin tssop, 4.40 mm body, 0.65 mm pitch) package dimensions are kept current with jedec publication no. 95 ordering information "lf" suffix to the part number are the pb -free configuration and are rohs compliant. while the information presented herein has been checked for both accuracy and reliability, integrated device technology (idt) a ssumes no responsibility for either its use or for the infringement of any paten ts or other rights of third parties, which would resul t from its use. no other circuits, patents, or licenses are im plied. this product is intended for use in normal commercial applications. any other applications such as those requiring extended temperature range, high reliab ility, or other extraordinary environmental requirements are not recommended without additional processing by idt. idt reserves th e right to change any circuitry or specifications without noti ce. idt does not authorize or warrant any idt product for use in life support devices or critical medical instruments. part / order number marking shipping packaging package temperature mk3722glf mk3722gl tubes 16-pin tssop 0 to +70 c MK3722GLFTR mk3722gl tape and reel 16-pin tssop 0 to +70 c index area 1 2 16 d e1 e seating plane a 1 a a 2 e - c - b .10 (.004) c c l millimeters inches symbol min max min max a--1.20--0.047 a1 0.05 0.15 0.002 0.006 a2 0.80 1.05 0.032 0.041 b 0.19 0.30 0.007 0.012 c 0.09 0.20 0.0035 0.008 d 4.90 5.1 0.193 0.201 e 6.40 basic 0.252 basic e1 4.30 4.50 0.169 0.177 e 0.65 basic 0.0256 basic l 0.45 0.75 0.018 0.030 0 8 0 8
? 2006 integrated device technology, inc. all rights reserved. product specifications subject to change without notice. idt and the idt logo are trademarks of integrated device technology, inc. accelerated thinking is a service mark of integrated device technology, inc. all other brands, product names a nd marks are or may be trademarks or registered trademarks used to identify products or services of their respective owners. printed in usa corporate headquarters integrated device technology, inc. www.idt.com for sales 800-345-7015 408-284-8200 fax: 408-284-2775 for tech support www.idt.com/go/clockhelp innovate with idt and accelerate your future netw orks. contact: www.idt.com mk3722 vcxo plus audio clock for stb vcxo and synthesizer
|
