AD9146 Analog Devices, AD9146 Datasheet - Page 33

• Manufacturer Part Number: AD9146
• Description: Dual, 16-Bit, 1230 MSPS, TxDAC+® Digital-to-Analog Converter
• Manufacturer: Analog Devices

Specifications of AD9146

• Resolution (bits): 16bit
• Dac Update Rate: 1.23GSPS
• Dac Settling Time: n/a
• Max Pos Supply (v): +3.47V
• Single-supply: No
• Dac Type: Current Out
• Dac Input Format: Byte,LVDS,Nibble

Data Sheet
Figure 41 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 and not
by the pass-band flatness. Table 16 shows the pass-band flatness
and the stop-band rejection supported by the HB1 filter at dif-
ferent bandwidths.
Table 16. HB1 Pass-Band and Stop-Band Performance by
Bandwidth
Bandwidth (% of f
80
80.4
81.2
82
83.6
85.6
Half-Band Filter 2 (HB2)
HB2 has eight modes of operation, as shown in Figure 42 and
Figure 43. 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.
–0.02
–0.04
–0.06
–0.08
–0.10
–100
0.02
–20
–40
–60
–80
0
0
0
0
MODE 0
0.04
0.2
0.08
Figure 41. Pass-Band Detail of HB1
0.4
Figure 42. HB2, Even Filter Modes
IN1
)
0.12
0.6
MODE 2
FREQUENCY (×
FREQUENCY (×
0.16
Pass-Band
Flatness (dB)
0.001
0.0012
0.0033
0.0076
0.0271
0.1096
0.8
0.20
1.0
0.24
MODE 4
f
f
IN2
1.2
IN1
) (Hz)
) (Hz)
0.28
1.4
0.32
1.6
Stop-Band
Rejection (dB)
85
80
70
60
50
40
MODE 6
0.36
1.8
0.40
2.0
Rev. A | Page 33 of 56
As shown in Figure 42 and Figure 43, the center frequency in
each mode is offset by one-fourth the input data rate (f
the filter. Mode 0 through Mode 3 do not modulate the input
signal. Mode 4 through Mode 7 modulate the input signal by
f
operate independently and no mixing of the data between chan-
nels occurs. When operating 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 to be complex. Table 17 summarizes
the HB2 modes.
Table 17. HB2 Filter Modes
Mode
0
1
2
3
4
5
6
7
IN2
. When operating in Mode 0 and Mode 4, the I and Q paths
–100
–20
–40
–60
–80
0
0
f
DC
f
f
3f
f
5f
3f
7f
0.2
IN
IN
IN
CENTER
IN
IN
IN
IN
/4
/2
/4
/4
/2
/4
MODE 1
0.4
Figure 43. HB2, Odd Filter Modes
0.6
FREQUENCY (×
f
None
None
None
None
f
f
f
f
IN
IN
IN
IN
MOD
0.8
MODE 3
1.0
f
IN2
1.2
MODE 5
) (Hz)
Input Data
Real or complex
Complex
Complex
Complex
Real or complex
Complex
Complex
Complex
1.4
MODE 7
1.6
1.8
AD9146
IN2
2.0
) of