AD9863 Analog Devices, AD9863 Datasheet - Page 15

• Manufacturer Part Number: AD9863
• Description: 12-Bit Mixed-Signal Front-End (MxFE® )Processor For Broadband Applications
• Manufacturer: Analog Devices

Specifications of AD9863

• Resolution (bits): 12bit
• # Chan: 2
• Sample Rate: 50MSPS
• Interface: Par
• Analog Input Type: Diff-Uni
• Ain Range: 2 V p-p
• Adc Architecture: Pipelined
• Pkg Type: CSP

Figure 34 to Figure 39 use the same input data to the Tx path, a 256-carrier OFDM signal over a 1.75 MHz bandwidth, centered at 7 MHz.
The four center carriers are removed from the signal to observe the in-band intermodulation distortion (IMD) from the DAC output.
Figure 34. AD9863 Tx Path FFT, 256-Carrier (Four Center Carriers Removed)
OFDM Signal over 1.75 MHz Bandwidth, Centered at 7 MHz, with
–100
–110
–120
–130
–100
–110
–120
–130
–100
–110
–120
–130
–30
–40
–50
–60
–70
–80
–90
–30
–40
–50
–60
–70
–80
–90
–30
–40
–50
–60
–70
–80
–90
Figure 35. AD9863 Tx Path FFT, Lower-Band IMD Products of
Figure 36. AD9863 Tx Path FFT of OFDM Signal in Figure 34,
6.06
6.0
0
20 mA Full-Scale Output into 60 Ω Differential Load
6.2
6.08
5
6.4
OFDM Signal in Figure 34
with 1× Interpolation
6.6
6.10
10
FREQUENCY (MHz)
FREQUENCY (MHz)
FREQUENCY (MHz)
6.8
6.12
7.0
15
7.2
6.14
7.4
20
6.16
7.6
25
7.8
6.18
8.0
Rev. A | Page 15 of 40
–100
–110
–120
–130
–100
–110
–120
–130
–100
–110
–120
–130
–30
–40
–50
–60
–70
–80
–90
–30
–40
–50
–60
–70
–80
–90
–30
–40
–50
–60
–70
–80
–90
Figure 38. AD9863 Tx Path FFT, Upper-Band IMD Products of
Figure 39. AD9863 Tx Path FFT of OFDM Signal in Figure 34,
6.97
7.81
Figure 37. AD9863 Tx Path FFT, In-Band IMD Products of
0
7.83
6.98
5
OFDM Signal in Figure 34
OFDM Signal in Figure 34
7.85
with 2× Interpolation
6.99
10
FREQUENCY (MHz)
FREQUENCY (MHz)
FREQUENCY (MHz)
7.87
7.00
15
7.89
7.01
20
7.91
7.02
25
7.93
AD9863
7.03