HI!
I am using AD9208 and HMC7044 together.
We are seeing spur in the FFT of the ADC output. the spur follows the Fs/2-Fin pattern and is -50dBc down which is greatly affecting the performance of AD9208.
As AD9208 is not an interleaving ADC, On inspecting the Clock input (i.e, Clock output from HMC7044), Fs/2 sub harmonics is present at a level of -40dBc down from Sampling clock of 2.94912GHz which is affecting our ADC performance.
Please find the attached HMC7044 Config file and HMC7044 Clock spectrum showing FS(2949.12MHz) and FS/2(1474.56MHz) spur.
Address Data
0x0000 0x01
0x0000 0x00
0x00A0 0xDF
0x00A5 0x06
0x00A8 0x06
0x00B0 0x04
0x0001 0x60
0x0003 0xB
0x0004 0x7F
0x0005 0x04
0x000A 0x00
0x000B 0x00
0x000C 0x01
0x000D 0x00
0x000E 0x07
0x0014 0xC9
0x0016 0x09
0x001A 0x0F
0x001C 0x01
0x001D 0x4
0x001E 0x01
0x001F 0x04
0x0020 0x04
0x0021 0xFA
0x0022 0x0
0x0026 0x0
0x0027 0xC
0x0028 0x1F
0x0029 0x10
0x002A 0x0F
0x0032 0x01
0x0033 0x01
0x0034 0x00
0x0035 0x18
0x0036 0x00
0x0037 0x0F
0x0046 0x00
0x0047 0x00
0x0048 0x00
0x0049 0x00
0x0050 0x1D
0x0051 0x29
0x0052 0x35
0x0053 0x00
0x0054 0x01
0x00C8 0x91
0x00C9 0x1
0x00CA 0x00
0x00CB 0x00
0x00CC 0x00
0x00CD 0x00
0x00CE 0x00
0x00CF 0x00
0x00D0 0x08
0x00D2 0x90
0x00D3 0x00
0x00D4 0x0F
0x00D5 0x00
0x00D6 0x00
0x00D7 0x00
0x00D8 0x00
0x00D9 0x00
0x00DA 0x30
0x00DC 0x91
0x00DD 0x1
0x00DE 0x00
0x00DF 0x00
0x00E0 0x00
0x00E1 0x00
0x00E2 0x00
0x00E3 0x00
0x00E4 0x01
0x00E6 0x90
0x00E7 0x00
0x00E8 0x0F
0x00E9 0x00
0x00EA 0x00
0x00EB 0x00
0x00EC 0x00
0x00ED 0x00
0x00EE 0x30
0x00F0 0x91
0x00F1 0x10
0x00F2 0x00
0x00F3 0x00
0x00F4 0x00
0x00F5 0x00
0x00F6 0x00
0x00F7 0x00
0x00F8 0x11
0x00FA 0x90
0x00FB 0x00
0x00FC 0x0F
0x00FD 0x00
0x00FE 0x00
0x00FF 0x00
0x0100 0x00
0x0101 0x00
0x0102 0x30
0x0104 0x91
0x0105 0x10
0x0106 0x00
0x0107 0x00
0x0108 0x00
0x0109 0x00
0x010A 0x00
0x010B 0x00
0x010C 0x01
0x010E 0x90
0x010F 0x00
0x0110 0x0F
0x0111 0x00
0x0112 0x00
0x0113 0x00
0x0114 0x00
0x0115 0x00
0x0116 0x30
0x0118 0x91
0x0119 0x10
0x011A 0x00
0x011B 0x00
0x011C 0x00
0x011D 0x00
0x011E 0x00
0x011F 0x00
0x0120 0x11
0x0122 0x90
0x0123 0x00
0x0124 0x0F
0x0125 0x00
0x0126 0x00
0x0127 0x00
0x0128 0x00
0x0129 0x00
0x012A 0x30
0x012C 0x91
0x012D 0x10
0x012E 0x00
0x012F 0x00
0x0130 0x00
0x0131 0x00
0x0132 0x00
0x0133 0x00
0x0134 0x11
0x0136 0x90
0x0137 0x00
0x0138 0x0F
0x0139 0x00
0x013A 0x00
0x013B 0x00
0x013C 0x00
0x013D 0x00
0x013E 0x30
0x0140 0x90
0x0141 0x0C
0x0142 0x00
0x0143 0x00
0x0144 0x00
0x0145 0x00
0x0146 0x00
0x0147 0x00
0x0148 0x11
0x014A 0x91
0x014B 0x10
0x014C 0x0
0x014D 0x0
0x014E 0x00
0x014F 0x00
0x0150 0x00
0x0151 0x00
0x0152 0x11
0x0001 0x66
0x0001 0x64
0x0001 0xE4
Please help us in reducing this spur level so that we can achieve the ADC performance claimed in AD9208 DS.
Thanks in-advance,
Deva
