Part Number: LMK04610
Other Parts Discussed in Thread: LMK04828, LMK04832
Tool/software:
We are using an LMK04610. We have a VCXO with good phase noise specs being locked to a very stable MEMS oscillator using PLL1. Both are 100M.
We’re aware that the LMK04610 will exhibit some phase drift in PLL1 between CLKIN and OSCIN, and have seen that on our board over temperature. We got this info from the following threads:
- LMK04610: Reference input to output apparent phase wander
- LMK04828: LMK04828 vs LMK04610
- LMK04610: Output clock phase is shifting by temperature change
The other thing we see, that is more troubling, is that the phase seems to slowly drift to a certain point, maybe on the order of 1 ns offset between MEMS osc and VCXO, and then the PLL appears to bounce the phase back and forth between the 1 ns offset and actual phase alignment at certain temperatures. This persists for some variable time depending on the specific part. We have observed this issue as a sudden jump in low frequency (below the bandwidth of the PLL1 loop) phase noise of 10+ dB that will appear and then disappear through temperature transients.
Is this phase popping back and forth a known issue? Is there some configuration change we can make to avoid or minimize it?
I've attached our config for reference.
R0 0x000000 R1 0x000100 R2 0x000200 R3 0x000346 R4 0x000438 R5 0x000503 R6 0x000611 R7 0x000700 R8 0x000800 R9 0x000900 R10 0x000A00 R11 0x000B00 R12 0x000C51 R13 0x000D08 R14 0x000E00 R15 0x000F00 R16 0x00103F R17 0x001100 R18 0x001206 R19 0x001310 R20 0x001400 R21 0x001508 R22 0x001630 R23 0x001700 R24 0x001800 R25 0x001931 R26 0x001A28 R31 0x001F00 R32 0x002078 R33 0x002100 R34 0x002278 R39 0x002714 R40 0x002808 R41 0x002914 R42 0x002A08 R43 0x002B00 R44 0x002C44 R45 0x002D00 R46 0x002E1E R47 0x002F41 R48 0x003002 R49 0x00313E R50 0x003200 R51 0x003300 R52 0x003443 R53 0x003510 R54 0x003603 R55 0x003710 R56 0x003803 R57 0x003910 R58 0x003A03 R59 0x003B00 R60 0x003C43 R61 0x003D40 R62 0x003E03 R63 0x003F40 R64 0x004003 R65 0x004140 R66 0x004203 R67 0x004300 R68 0x00440C R69 0x004501 R70 0x004680 R71 0x004700 R72 0x004803 R73 0x004901 R74 0x004A80 R75 0x004B00 R76 0x004C06 R77 0x004D00 R78 0x004E08 R79 0x004F00 R80 0x005008 R81 0x005100 R82 0x005208 R83 0x005300 R84 0x005410 R85 0x005500 R86 0x00560F R87 0x005700 R88 0x00583F R89 0x005961 R90 0x005A0A R91 0x005B02 R92 0x005C0E R93 0x005D00 R94 0x005E00 R95 0x005F61 R96 0x0060A8 R97 0x006100 R98 0x006278 R99 0x006300 R100 0x006440 R101 0x006500 R102 0x006600 R103 0x006700 R104 0x006800 R105 0x006900 R106 0x006A09 R107 0x006B01 R108 0x006C00 R109 0x006D08 R110 0x006EC3 R111 0x006F00 R112 0x007000 R113 0x007100 R114 0x007214 R115 0x007300 R116 0x00740F R117 0x007500 R118 0x007601 R119 0x007701 R120 0x0078FF R121 0x007900 R122 0x007A86 R123 0x007BA0 R124 0x007C08 R125 0x007D00 R126 0x007E00 R127 0x007F34 R128 0x00800A R129 0x008100 R130 0x008200 R131 0x008300 R132 0x00840F R133 0x008501 R134 0x008601 R135 0x008700 R136 0x008840 R137 0x008900 R138 0x008A00 R139 0x008B40 R140 0x008C00 R141 0x008D00 R142 0x008E00 R143 0x008F40 R144 0x009000 R145 0x009100 R146 0x009280 R147 0x009380 R148 0x009412 R149 0x009504 R150 0x009610 R151 0x009720 R152 0x009860 R153 0x009980 R155 0x009B00 R156 0x009C20 R171 0x00AB00 R172 0x00AC00 R173 0x00AD00 R175 0x00AF01 R176 0x00B001 R190 0x00BE03 R246 0x00F600 R247 0x00F700 R249 0x00F907 R250 0x00FAD7 R252 0x00FC00 R253 0x00FD00 R254 0x00FE00 R255 0x00FF00 R256 0x010000 R257 0x010100 R258 0x010200 R259 0x010300 R260 0x010400 R261 0x010500 R262 0x010600 R263 0x010700 R264 0x010800 R265 0x010900 R266 0x010A00 R267 0x010B00 R269 0x010D00 R270 0x010E00 R272 0x011000 R273 0x011100 R274 0x011200 R277 0x011500 R278 0x011600 R279 0x011700 R281 0x011900 R282 0x011A00 R292 0x012408 R295 0x012704 R296 0x012801 R297 0x012905 R298 0x012A01 R299 0x012B04 R300 0x012C05 R301 0x012D04 R302 0x012E01 R304 0x013005 R305 0x013105 R307 0x013305 R308 0x013405 R309 0x013505 R312 0x013805 R313 0x013905 R314 0x013A05 R316 0x013C05 R317 0x013D05 R320 0x01400A R321 0x014100 R322 0x014200 R323 0x014300 R325 0x014500 R326 0x01461C R329 0x014900 R330 0x014A00 R331 0x014B00 R332 0x014C00 R334 0x014E00 R336 0x015000 R337 0x015114 R338 0x01520F R339 0x015300
