AD9139
Data Sheet
Table 13. DLL Phase Setup and Hold Times (Typical)
Frequency,
Data Port Setup and Hold Times (ps) at DLL Phase
fDCI1
Time
(MHz)
(ps)
−6 −5 −4 −3 −2 −1 0
+1 +2
+3
250
tS
−93 −196 −312 −416 −530 −658 −770 −878 −983 −1093
tH
468 579 707 825 947 1067 1188 1315 1442 1570
275
tS
−87 −172 −264 −364 −464 −556 −653 −756 −859 −956
tH
451 537 646 757 878 977 1092 1218 1311 1423
300
tS
−82 −166 −256 −341 −426 −515 −622 −715 −809 −900
tH
422 500 598 703 803 897 1000 1105 1203 1303
325
tS
−46 −114 −190 −271 −358 −447 −538 −612 −706 −806
tH
405 483 563 647 740 832 914 1000 1100 1200
350
tS
−23 −92 −180 −252 −328 −409 −491 −574 −654 −731
tH
383 451 524 607 682 762 844 930 1011 1097
375
tS
−7 −82 −150 −225 −315 −391 −461 −526 −595 −661
tH
401 466 504 569 641 718 783 863 941 1025
400
tS
−46 −98 −161 −243 −303 −384 −448 −513 −578 −643
tH
385 445 503 546 604 674 748 826 890 965
425
tS
4
−52 −110 −170 −229 −297 −394 −449 −517 −579
tH
358 408 465 524 595 625 692 762 829 900
450
tS
11
−34 −92 −147 −209 −269 −324 −386 −446 −509
tH
354 406 457 516 573 637 693 731 792 852
475
tS
−15 −51 −95 −147 −198 −255 −313 −366 −425 −480
tH
355 399 451 499 556 613 675 727 779 815
500
tS
9
−28 −77 −128 −183 −233 −288 −333 −390 −438
tH
313 354 399 445 500 555 615 668 726 783
525
tS
−7 −52 −100 −147 −187 −237 −285 −335 −387 −436
tH
311 356 395 438 489 537 592 645 692 746
550
tS
−5 −39 −74 −107 −147 −192 −249 −302 −352 −397
tH
300 340 378 423 468 510 560 610 659 710
575
tS
8
−28 −66 −102 −143 −181 −245 −280 −336 −366
tH
312 348 379 414 453 496 544 599 654 708
+4
−1193
1697
−1053
1537
−1001
1411
−891
1292
−819
1186
−726
1106
−713
1039
−641
966
−564
917
−530
873
−495
825
−483
799
−440
756
−406
759
+5
−1289
1777
−1151
1653
−1097
1522
−966
1380
−889
1277
−786
1187
−771
1110
−704
1032
−622
983
−585
930
−545
881
−530
850
−486
810
−443
806
+6
−1412
1876
−1251
1728
−1184
1612
−1044
1476
−959
1358
−853
1264
−833
1178
−752
1097
−672
1042
−640
988
−594
934
−581
909
−529
865
−488
847
1 Table 13 shows characterization data for selected fDCI frequencies. Other frequencies are possible; use Table 13 to estimate performance.
Table 13 shows the typical times for various DCI clock frequencies
that are required to calculate the data valid margin. Use Table 13 to
Register 0x0D optimizes the DLL stability over the operating
frequency range. Table 14 shows the recommended settings.
determine the amount of margin that is available for tuning of
the DSC sampling point.
Table 14. DLL Configuration Options
DCI Speed
Register 0x0D
Maximizing the opening of the eye in both the DCI and data
≥350 MHz
0x06
signals improves the reliability of the data port interface. Use
<350 MHz
0x86
differential controlled impedance traces of equal length (that is,
delay) between the host processor and the AD9139 input. To
Poll the status of the DLL by reading the data status register at
ensure coincident transitions with the data bits, implement the
Address 0x0E. Bit 0 indicates that the DLL is running and
DCI signal as an additional data line with an alternating
attempting lock; Bit 7 is 1 when the DLL has locked. Bit 2 is 1
(010101…) bit sequence from the same output drivers that are
when a valid data clock input (DCI) is detected. The warning
used for the data.
bits in [6:4] in Register 0x0E can be used as indicators that the
The DCI signal is ac-coupled by default; thus, removing the
DCI signal may cause DAC output chatter due to randomness
on the DCI input. To avoid this, disable the DAC output
whenever the DCI signal is not present by setting the DAC output
current power-down bit in Register 0x01[7] to 1. When the DCI
DAC may be operating in a nonideal location in the delay line.
Note that these bits are read at the SPI port speed, which is
much slower than the actual speed of the DLL. This means they
can only show a snapshot of what is happening as opposed to
giving real-time feedback.
signal is again present, enable the DAC output by programming
Register 0x01[7] to 0.
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