AD9125 Analog Devices, AD9125 Datasheet - Page 33

• 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

Figure 52 shows the pass-band filter response for HB1. In most
applications, the usable bandwidth of the filter is limited by the
image suppression provided by the stop-band rejection, not by
the pass-band flatness. Table 17 shows the pass-band flatness
and stop-band rejection that the HB1 filter supports at different
bandwidths.
Table 17. HB1 Pass-Band Flatness and Stop-Band Rejection
Bandwidth (% of f
80
80.4
81.2
82.0
83.6
85.6
–0.02
–0.04
–0.06
–0.08
–0.10
0.02
0
0
0.04
Figure 52. Pass-Band Detail of HB1
0.08
IN1
NORMALIZED FREQUENCY (×
)
0.12
0.16
Pass-Band
Flatness (dB)
0.001
0.0012
0.0033
0.0076
0.0271
0.1096
0.20
0.24
0.28
0.32
f
IN1
Stop-Band
Rejection (dB)
85
80
70
60
50
40
)
0.36
0
.
40
Rev. 0 | Page 33 of 56
Half-Band Filter 2 (HB2)
HB2 has eight modes of operation, as shown in Figure 53 and
Figure 54. The shape of the filter response is identical in each of
the eight modes. The eight modes are distinguished by two factors:
the filter center frequency and whether the input signal is
modulated by the filter.
As shown in Figure 53 and Figure 54, the center frequency in
each mode is offset by ¼ of the input data rate (f
Mode 0 through Mode 3 do not modulate the input signal.
Mode 4 through Mode 7 modulate the input signal by f
When HB2 operates in Mode 0 and Mode 4, the I and Q paths
operate independently and no mixing of the data between
channels occurs. When HB2 operates in the other six modes,
mixing of the data between the I and Q paths occurs; therefore,
the data input to the filter is assumed complex.
–100
–100
–20
–40
–60
–80
–20
–40
–60
–80
0
0
0
0
MODE 0
0.2
0.2
MODE 1
0.4
Figure 53. HB2, Even Filter Modes
0.4
Figure 54. HB2, Odd Filter Modes
NORMALIZED FREQUENCY (×
NORMALIZED FREQUENCY (×
0.6
0.6
MODE 2
0.8
0.8
MODE 3
1.0
1.0
MODE 4
1.2
1.2
MODE 5
1.4
1.4
f
f
IN2
IN2
MODE 7
)
)
1.6
1.6
MODE 6
IN2
) of the filter.
1.8
1.8
AD9125
IN2
2
2
.0
.0
.