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AD9517-3 lock issue

Question asked by smutha on Jan 5, 2016
Latest reply on Jan 14, 2016 by smutha

Hello,

         The problem is that the PLL is not locked and the output freq is not correct.

We have a 200MHz differential reference in and the loop filter is same as that on the eval board.

Reset is pulled high and Ref_Sel is tied low.

After writing all the registers once 0x018(0) is set to 1.

Then 0x01F is read and the result is 0x0E (VCO cal not done and no lock).

CP out pin is at 0V and bypass pin cap is at ~2.6V.

 

Thank you for your help,

 

The register settings are as follows: (For 125MHz CMOS out on o/p5)

 

AD9516/17/18 Register Map File, Rev 1.0

 

 

 

Addr(Hex)     Value(Bin)    Value(Hex)

0000          00011000      18

0001          00000000      00

0002          00010000      10

0003          01010011      53

0004          00000000      00

0010          01111100      7C

0011          11001000      C8

0012          00000000      00

0013          00000000      00

0014          01111101      7D

0015          00000000      00

0016          00000101      05

0017          00000000      00

0018          00000110      06

0019          00000000      00

001A          00000000      00

001B          00000000      00

001C          01000000      87

001D          00000000      00

001E          00000000      00

001F          00001110      0E

00A0          00000001      01

00A1          00000000      00

00A2          00000000      00

00A3          00000001      01

00A4          00000000      00

00A5          00000000      00

00A6          00000001      01

00A7          00000000      00

00A8          00000000      00

00A9          00000001      01

00AA          00000000      00

00AB          00000000      00

00F0          00001010      0A

00F1          00001010      0A

00F2          00001000      08

00F3          00001010      0A

00F4          00001010      0A

00F5          00001010      0A

0140          01000011      43

0141          01011010      5A

0142          01000011      43

0143          01000011      43

0190          00000000      00

0191          10000000      80

0192          00000000      00

0193          10111011      BB

0194          00000000      00

0195          00000000      00

0196          00000000      00

0197          00000000      00

0198          00000000      00

0199          00000000      00

019A          00000000      00

019B          00000000      00

019C          00000000      00

019D          00000000      00

019E          00100010      22

019F          00000000      00

01A0          00010001      11

01A1          00000000      00

01A2          00000000      00

01A3          00000000      00

01E0          00000010      02

01E1          00000010      02

0230          00000000      00

0231          00000000      00

0232          00000000      00

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