AD9125 Analog Devices, AD9125 Datasheet - Page 36

• Manufacturer Part Number: AD9125
• Manufacturer: Analog Devices

Specifications of AD9125

• Resolution (bits): 16bit
• Dac Update Rate: 1GSPS
• Dac Settling Time: n/a
• Max Pos Supply (v): +3.47V
• Single-supply: No
• Dac Type: Current Out
• Dac Input Format: Par

AD9125
Table 21. Recommended Interpolation Filter Modes (Register 0x1C through Register 0x1E)
Interpolation Factor
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
4
4
4
4
4
4
4
4
2
2
2
2
1
2
3
When HB1 Mode 1 or Mode 3 is used, enabling premodulation provides an addition frequency translation of the input signal by f
input signal in the filter pass band.
This configuration was used in the 8× interpolation without NCO example. In addition, see the 8× Interpolation Without NCO section.
This configuration was used in the 4× interpolation with NCO example. In addition, see the 4× Interpolation with NCO section
2
3
Figure 59. Signal Bandwidth vs. Center Frequency of the Output Signal,
0.8
0.6
0.5
0.1
HB1, HB2, AND HB3
0.25
8× Interpolation
0.4
f
0.50
OUT
/
f
DATA
0.6
HB1[1:0]
00 (0)
01 (1)
10 (2)
11 (3)
00 (0)
01 (1)
10 (2)
11 (3)
00 (0)
01 (1)
10 (2)
11 (3)
00 (0)
01 (1)
10 (2)
11 (3)
00 (0)
01 (1)
10 (2)
11 (3)
00 (0)
01 (1)
10 (2)
11 (3)
00 (0)
01 (1)
10 (2)
11 (3)
0.75
0.9
HB2[5:0]
000000
001001
010010
011011
100100
101101
110110
111111
000000
001001
010010
011011
100100
101101
110110
111111
000000
001001
010010
011011
100100
101101
110110
111111
Bypass
Bypass
Bypass
Bypass
1.00
Filter Modes
Rev. 0 | Page 36 of 56
HB3[5:0]
000000
000000
001001
001001
010010
010010
011011
011011
100100
100100
101101
101101
110110
110110
111111
111111
Bypass
Bypass
Bypass
Bypass
Bypass
Bypass
Bypass
Bypass
Bypass
Bypass
Bypass
Bypass
DETERMINING INTERPOLATION FILTER MODES
Table 21 shows the recommended interpolation filter settings
for a variety of filter interpolation factors, filter center frequencies,
and signal modulation. The interpolation modes were chosen
based on the final center frequency of the signal and by
determining the frequency shift of the signal required. When
these are known and put in terms of the input data rate (f
the filter configuration that comes closest to matching should
be chosen from Table 21.
2 × f
2 × f
3 × f
4 × f
4 × f
5 × f
5 × f
6 × f
6 × f
7 × f
7 × f
2 × f
2 × f
3 × f
3 × f
f
DC
DC
f
f
3 × f
DC
DC
f
f
DC
DC
f
f
DATA
DATA
DATA
DATA
DATA
DATA
SIGNAL
1
1
1
1
1
1
DATA
DATA
DATA
DATA
DATA
DATA
DATA
DATA
DATA
DATA
DATA
DATA
DATA
DATA
DATA
DATA
Modulation
1
1
1
1
1
1
1
1
DATA
/2, which centers a baseband
0
f
0
f
f
3 × f
2 × f
5 × f
3 × f
7 × f
4 × f
9 × f
5 × f
11 × f
6 × f
13 × f
7 × f
15 × f
0
f
f
3 × f
2 × f
5 × f
3 × f
7 × f
f
f
3 × f
DATA
DATA
DATA
DATA
DATA
DATA
CENTER
/2
/2
/2
DATA
DATA
DATA
DATA
DATA
DATA
DATA
DATA
DATA
DATA
DATA
DATA
DATA
DATA
DATA
DATA
DATA
DATA
DATA
Shift
/2
/2
/2
/2
/2
/2
/2
/2
/2
/2
/2
DATA
),