AD6620–Typical Performance Characteristics
400
0
375
–20
350
325
300
275
RCF DECIMATION
–40
–60
–80
CIC5 DECIMATION
–100
–120
–140
CIC2 DECIMATION
250
225
1
2
3
4
5
0
1
2
3
LOG (M)
2
COMPOSITE FREQUENCY RESPONSE – MHz
TPC 1. Typical Power vs. Decimation Rates
TPC 4. High Decimation GSM Filter
Input sample rate 65 MSPS, decimation is 240, FIR taps is 240.
Unshown spectrum is below that shown. Decimation distribu-
tion is 3, 10, 8, respectively.
0
SPUR = –104dB
PHASE DITHER OFF
–12
–24
–36
–48
–60
–72
–84
–96
–108
0
–20
–40
–60
–80
–100
–120
–140
–120
–132
0
f
SAMP
TPC 2. Typical NCO Spur Without Dither
0
2
4
6
8
0
–12
–24
–36
–48
–60
–72
–84
–96
–108
COMPOSITE FREQUENCY RESPONSE – MHz
SPUR = –118dB
PHASE DITHER ON
TPC 5. High Decimation AMPS Filter
Input sample rate 58.32 MSPS, decimation is 300, FIR taps is
128. Unshown spectrum is below that shown. Decimation distri-
bution among CIC2, CIC5, and RCF is 10, 30 and 1, respectively.
–120
–132
0
f
SAMP
TPC 3. Typical NCO Spur with Dither
REV. A
–14–
ADI [ ADI ]
