ad80164absvz Analog Devices, Inc., ad80164absvz Datasheet - Page 32

• Manufacturer Part Number: ad80164absvz
• Description: Dual, 12-/14-/16-bit,1 Gsps Digital-to-analog Converters
• Manufacturer: Analog Devices, Inc.

AD9776A/AD9778A/AD9779A
With the interpolation filter and modulator combined, the
incoming signal can be placed anywhere within the Nyquist
region of the DAC output sample rate. When the input signal
is complex, this architecture allows modulation of the input
signal to positive or negative Nyquist regions (see Table 18).
The Nyquist regions of up to 4× the input data rate can be seen
in Figure 60.
Figure 57, Figure 58, and Figure 59 show the low-pass response
of the digital filters with no modulation. By turning on the modu-
lation feature, the response of the digital filters can be tuned to
anywhere within the DAC bandwidth. As an example, Figure 61
to Figure 67 show the nonshifted mode filter responses (refer to
Table 18 for shifted/nonshifted mode filter responses).
Figure 58. 4× Interpolation, Low-Pass Response to ±4× Input Data Rate
Figure 59. 8× Interpolation, Low-Pass Response to ±4× Input Data Rate
–100
–100
–10
–20
–30
–40
–50
–60
–70
–80
–90
–10
–20
–30
–40
–50
–60
–70
–80
–90
–4×
10
10
0
0
–8
–4
–4
–7
–3×
–6
–3
–3
(Dotted Lines Indicate 1 dB Roll-Off)
(Dotted Lines Indicate 1 dB Roll-Off)
–5
–2×
–4
–2
–2
Figure 60. Nyquist Zones
–3
–1×
f
f
OUT
OUT
–2
–1
–1
–1
(× Input Data Rate)
(× Input Data Rate)
DC
1
0
0
2
1×
3
1
1
4
2×
5
2
2
6
3×
7
8
3
3
4×
4
4
Rev. 0 | Page 32 of 68
Figure 62. Interpolation/Modulation Combination of −3f
Figure 63. Interpolation/Modulation Combination of −2f
Figure 61. Interpolation/Modulation Combination of 4f
–100
–100
–100
–10
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–30
–40
–50
–60
–70
–80
–90
–10
–20
–30
–40
–50
–60
–70
–80
–90
–10
–20
–30
–40
–50
–60
–70
–80
–90
10
10
10
0
0
0
–4
–4
–4
–3
–3
–3
–2
–2
–2
f
f
f
OUT
OUT
OUT
–1
–1
–1
(× Input Data Rate)
(× Input Data Rate)
(× Input Data Rate)
0
0
0
1
1
1
2
2
2
DAC
3
3
DAC
3
DAC
/8 Filter
/8 Filter
/8 Filter
4
4
4