MK1491-09 mds 1491-09 g 1 revision 080204 integrated circuit systems, inc. 525 race street, san jose, ca 95126 tel (408) 297-1201 www.icst.com amd geode? gx2 clock source description the MK1491-09 is a low-cost, low-jitter, high-performance clock synthesizer for amd?s geode-based computer and portable appliance applications. using patented analog phased-locked loop (pll) techniques, the device accepts a 14.318 mhz crystal input to produce multiple output clocks. it provides selectable pci local bus clocks, 48 mhz clocks for super i/o and usb, as well as multiple reference outputs. the device has multiple power-down modes to reduce power consumption. features ? packaged in 28-pin ssop (209 mil body) ? available in pb (lead) free packaged ? provides all critical timing for the amd geode companion chip ? four selectable pci clocks ? three lpc interface clocks ? one fixed 66 mhz clock ? 2 reference clocks ? 48 mhz usb and 48 mhz io support ? power down mode ? low emi enable pin reduces emi radiation on pci clocks, lclks, and 66 mhz clock ? operating voltage of 3.3 v 5% block diagram crystal oscillator usb clock clocks sel66/33# pd# vdd gnd 6 6 3 lclk (33 mhz) 66 mhz 48 mhz refclk1 refclk0/spread# 48/ts# 14.31818 mhz crystal xi xo pci (66/33 mhz) 4
amd geode? gx2 clock source mds 1491-09 g 2 revision 080204 integrated circuit systems, inc. 525 race street, san jose, ca 95126 tel (408) 297-1201 www.icst.com MK1491-09 pin assignment pci frequency select table emi control spread direction is down. pin descriptions key: i = input, ti = tri-level, o = output, p = power supply connection, (t)i/o = input on power up, becomes an output after 10 ms, weak internal pull-up resistors are present on ts#, spread#, pd#, and sel66/33. 18 7 17 8 16 9 15 gnd 10 vdd 11 lclk2/33m 12 gnd 13 sel66/33# 14 gnd vdd pciclk0/33-66m vdd pd# gnd 48m 66m 22 21 20 19 48m/ts# gnd 5 6 lclk0/33m lclk1/33m 24 23 3 4 xo vdd vdd 26 25 refclk1 1 2 gnd xi refclk0/spread# 28 27 vdd pciclk1/33-66m pciclk2/33-66m pciclk3/33-66m sel66/33# pci frequency 033 mhz 166 mhz spread# pci low emi 0on 1off pin number pin name pin type pin description 1, 7, 11, 15, 21, 22 gnd p connect to ground. 2 xi i crystal connection. connect to a 14.31818 mhz crystal or input clock. 3 xo o crystal connection. connect to a 14.31818 mhz crystal, or leave unconnected. 4, 8, 12, 19, 25, 28 vdd p connect to 3.3 v. 5, 6, 9 lclk o 33 mhz low skew clock outputs. 10 sel66/33# i selects frequency on pciclk. 13 48m o 48 mhz clock output. 14 48m/ts# i/o 48 mhz clock output. ts# is high at power-up. 16 66m o 66 mhz clock output. 17 pd# i power-down input (see table on page 3). 18, 20, 23, 24 pciclk o 33 to 66 mhz pci synchronous clock outputs with low skew. 26 refclk1 o buffered reference output of 14.31818 mhz. 27 refclk0/ spread# i/o buffered reference output of 14.31818 mhz. spread select at power-up. for spread#, see table above.
amd geode? gx2 clock source mds 1491-09 g 3 revision 080204 integrated circuit systems, inc. 525 race street, san jose, ca 95126 tel (408) 297-1201 www.icst.com MK1491-09 power down control table power-on default conditions pd# functions 0 all clocks are stopped low. 1 all clocks are running. pin # function default condition 14 ts# h all outputs enabled. 27 spread# h spread disabled. 17 pd# h pci clocks set to 33.3 mhz. refer to power down control table above. 10 sel66/33 h pci frequency = 66 mhz.
amd geode? gx2 clock source mds 1491-09 g 4 revision 080204 integrated circuit systems, inc. 525 race street, san jose, ca 95126 tel (408) 297-1201 www.icst.com MK1491-09 external components the MK1491-09 requires some inexpensive external components for proper operation. decoupling capacitors of 0.1f should be connected on each vdd pin to ground, as close to the MK1491-09 as possible. a series termination resistor of 33 ? may be used for each clock output. see the discussion below for other external resistors required for proper i/o operation. the 14.318 mhz oscillator has in ternal caps that provide the proper load for a parallel resonant crystal with cl=18 pf. for tuning with other values of c l , the formula 2*(c l -18) gives the value of each capacitor that should be connected between x1 and ground and x2 and ground. i/o structure the MK1491-09 provides more functionality in a 28-pin package by using a unique i/o technique. the device checks the status of all i/o pins during power-up. this status (pulled high or low) then determines the frequency selections and power down modes (see the tables on pages 2 and 3). within 10ms after power up, the inputs change to outputs and the clocks start up. in the diagrams below, the 33 ? resistors are the normal output termination resistors. the 10k ? resistor pulls low to generate a logic zero when needed. weak internal pull-up resistors are present on ts#, spread#, pd#, and sel66/33 to pull the pin to high when left floating. *note: do not use a ttl load. this will overcome the 10 k ? pull-down and force the input to a logic 1. 33 to load* 10 k i/o for select = 0 (low) do not stuff for ?1? selection
amd geode? gx2 clock source mds 1491-09 g 5 revision 080204 integrated circuit systems, inc. 525 race street, san jose, ca 95126 tel (408) 297-1201 www.icst.com MK1491-09 absolute maximum ratings stresses above the ratings listed below can cause permanent damage to the MK1491-09. these ratings, which are standard values for ics 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 extended periods can affect product reliability. electrical parameters are guaranteed only over the recommended operating temperature range. dc electrical characteristics unless stated otherwise, vdd = 3.3 v , ambient temperature 0 to +70 c item rating supply voltage, vdd (r eferenced to vss) 4.6 v all inputs and outputs (referen ced to vss) -0.5 v to vdd+0.5 v ambient operating temperature 0 to +70 c storage temperature -65 to +150 c junction temperature 125 c soldering temperature (10 seconds max) 260 c spread spectrum enabled for pci and lpc clocks 30 khz min., 33 khz max. parameter symbol conditions min. typ. max. units operating voltage vdd 3.13 3.3 3.46 v input high voltage v ih 2vddv input low voltage v il vss 0.8 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 operating supply current idd vdd = 3.3 v 60 ma clock disable mode supply current 0.5 ma internal pull-up resistor all inputs except xi k ? input capacitance c in all inputs except xi 5 pf
amd geode? gx2 clock source mds 1491-09 g 6 revision 080204 integrated circuit systems, inc. 525 race street, san jose, ca 95126 tel (408) 297-1201 www.icst.com MK1491-09 ac electrical characteristics unless stated otherwise, vdd = 3.3 v , ambient temperature 0 to +70 c note 1: only valid when pci is at 33 mhz. thermal characteristics parameter symbol conditions min. typ. max. units input frequency f in 14.31818 mhz output clock skew rate (pci and lpc), load = 30 pf between 0.4 v and 2.4 v 4 v/ns output clock rise and fall time (all but pci and lpc), load=pf t or, t of between 0.4 v and 2.4 v 0.5 2 ns output clock duty cycle, all mhz clocks t od at 1.5 v 40 60 % pci output to output skew, at 33 mhz rising edges at 1.5 v 500 ps pci output to output skew, at 66 mhz rising edges at 1.5 v 250 ps lpc output to output skew rising edges at 1.5 v 500 ps pci to lpc output to output skew (note 1) rising edge at 1.5 v 500 ns cycle-to-cycle jitter, pciclk 300 ps cycle-to-cycle jitter, lpcclk 500 ps cycle-to-cycle jitter, usbclk and 48 mhz 500 ps cycle-to-cycle jitter, refclks 1400 ps power-on time, applied vdd to all clocks stable 5ms load capacitance crystal 18 pf parameter symbol conditions min. typ. max. units thermal resistance junction to ambient ja still air 100 c/w ja 1 m/s air flow 80 c/w ja 3 m/s air flow 67 c/w thermal resistance junction to case jc 60 c/w
amd geode? gx2 clock source mds 1491-09 g 7 revision 080204 integrated circuit systems, inc. 525 race street, san jose, ca 95126 tel (408) 297-1201 www.icst.com MK1491-09 marking diagram marking diagram (for pb free) notes: 1. ###### is the lot code. 2. yyww is the last two digits of the year, and the week number that the part was assembled. 3. ?ln? designates pb (lead) free. 14 28 15 MK1491-09f ###### yyww ics 1 14 28 15 MK1491-09fln ###### yyww ics 1
amd geode? gx2 clock source mds 1491-09 g 8 revision 080204 integrated circuit systems, inc. 525 race street, san jose, ca 95126 tel (408) 297-1201 www.icst.com MK1491-09 package outline and package dimensions (28-pin ssop, 209 mil body) package dimensions are kept current with jedec publication no. 95, mo-150 ordering information note: 1. ?l? designates pb (lead) free. while the information presented herein has been checked for both accuracy and reliability, integrated circuit systems (ics) assumes no responsibility for either its use or for the infringemen t of any patents or other rights of third parties, which wou ld result from its use. no other circuits, patents, or licenses are implied. this product is intended for use in normal commercial applications. any other applications such as those requiring ex tended temperature range, high re liability, or other extraordina ry environmental requirements are not recomm ended without additional processing by ics. ics reserves the right to change any circuitry or specifications without notice. ics does not authorize or warrant any ics product for use in life support devices o r critical medical instruments. part / order number marking (see note 1) low emi feature shipping packaging package temperature MK1491-09f MK1491-09f yes tubes 28-pin ssop 0 to +70 c MK1491-09ftr MK1491-09f yes tape and reel 28-pin ssop 0 to +70 c MK1491-09fln MK1491-09fln yes tubes 28-pin ssop 0 to +70 c MK1491-09flntr MK1491-09fln yes tape and reel 28-pin ssop 0 to +70 c index area 1 2 28 d e1 e seating plane a1 a a2 e - c - b c l millimeters inches symbol min max min max a ? 2.00 ? 0.079 a1 0.05 ? 0.002 ? a2 1.65 1.85 0.065 0.073 b 0.22 0.38 0.009 0.015 c 0.09 0.25 0.0035 0.010 d 9.90 10.50 0.390 0.413 e 7.40 8.20 0.291 0.323 e1 5.00 5.60 0.197 0.220 e 0.65 basic 0.0256 basic l 0.55 0.95 0.022 0.037 0 8 0 8 the controlling dime nsions is inches
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