Datasheet

AD9776/AD9778/AD9779
Rev. A | Page 34 of 56
Table 17. Interpolation Filter Modes, (Register 0x01, Bits<5:2>)
Interpolation
Factor <7:6>
Filter
Mode
<5:2>
Modulation
Nyquist
Zone
Pass
Band
F_Low
1
Center
1
F_High
1
Comments
8 0x00 DC 1 −0.05 0 +0.05
8 0x01 DC shifted 2 0.0125 0.0625 0.1125
8 0x02 F/8 3 0.075 0.125 0.175
8 0x03 F/8 shifted 4 0.1375 0.1875 0.2375
8 0x04 F/4 5 0.2 0.25 0.3
8 0x05 F/4 shifted 6 0.2625 0.3125 0.3625
8 0x06 3F/8 7 0.325 0.375 0.425
8 0x07 3F/8 shifted 8 0.3875 0.4375 0.4875
8 0x08 F/2 −8 −0.55 −0.5 −0.45
8 0x09 F/2 shifted −7 −0.4875 −0.4375 −0.3875
8 0x0A −3F/8 −6 −0.425 −0.375 −0.343
8 0x0B −3F/8 shifted −5 −0.3625 −0.3125 −0.2625
8 0x0C −F/4 −4 −0.3 −0.25 −0.2
8 0x0D −F/4 shifted −3 −0.2375 −0.1875 −0.1375
8 0x0E −F/8 −2 −0.175 −0.125 −0.075
8 0x0F −F/8 shifted −1 −0.1125 −0.0625 −0.0125
In 8× interpolation;
BW (min) = 0.0375 × f
DAC
BW (max) = 0.1 × f
DAC
4 0x00 DC 1 −0.1 0 +0.1
4 0x01 DC shifted 2 0.025 0.125 0.225
4 0x02 F/4 3 0.15 0.25 0.35
4 0x03 F/4 shifted 4 0.275 0.375 0.475
4 0x04 F/2 −4 −0.6 −0.5 −0.4
4 0x05 F/2 shifted −3 −0.475 −0.375 −0.275
4 0x06 −F/4 −2 −0.35 −0.25 −0.15
4 0x07 −F/4 shifted −1 −0.225 −0.125 −0.025
In 4× interpolation;
BW (min) = 0.075 × f
DAC
BW (max) = 0.2 × f
DAC
2 0x00 DC 1 −0.2 0 +0.2
2 0x01 DC shifted 2 0.05 0.25 0.45
2 0x02 F/2 −2 −0.7 −0.5 −0.3
2 0x03 F/2 shifted −1 −0.45 −0.25 −0.05
In 2× interpolation;
BW (min) = 0.15 × f
DAC
BW (max) = 0.4 × f
DAC
1
Frequency normalized to f
DAC
.