AD9125-M5372-EBZ Analog Devices Inc, AD9125-M5372-EBZ Datasheet - Page 15

• Manufacturer Part Number: AD9125-M5372-EBZ
• Description: 16-BIT DAC Evaluation Board
• Manufacturer: Analog Devices Inc

Specifications of AD9125-M5372-EBZ

• Silicon Manufacturer: Analog Devices
• Application Sub Type: DAC
• Kit Application Type: Data Converter
• Silicon Core Number: AD9125
• Features: Come With Clocking And Analog Quadrature Modulator Circuits
• Kit Contents: Quick Start Guide, Board, Software Updates
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

An example is shown in Figure 32 with a third-order, elliptical,
low-pass filter with a 3 dB frequency of 3 MHz. Matching input
and output impedances makes the filter design easier, so the
shunt resistor chosen is 100 Ω, producing an ac swing of
1 V p-p differential.
USING THE AD9779 AUXILIARY DAC FOR CARRIER
FEEDTHROUGH NULLING
The
inject small currents into the differential outputs for each main
DAC channel. This feature can be used to produce the small
offset voltages necessary to null out the carrier feedthrough
from the modulator. Figure 33 shows the interface required
to use the auxiliary DACs. This adds four resistors to the
interface.
AD9779
AD9779
OUT1_N
AUX1_N
AUX2_N
OUT2_N
AUX1_P
OUT1_P
OUT2_P
AUX2_P
OUT1_N
OUT2_N
OUT1_P
OUT2_P
AD9779
Figure 33. DAC Modulator Interface with Auxiliary DAC Resistors
500Ω
92
500Ω
500Ω
90
93
89
500Ω
87
84
83
86
93
92
84
83
features an auxiliary DAC that can be used to
RBQN
RBQP
3 MHz Third-Order, Elliptical Low-Pass Filter
RBQN
RBQP
RBIP
RBIN
RBIN
RBIP
50Ω
50Ω
50Ω
50Ω
Figure 32. DAC Modulator Interface with
50Ω
50Ω
50Ω
50Ω
250Ω
250Ω
250Ω
250Ω
1.1nF
1.1nF
1.1nF
1.1nF
C1Q
C1I
C1Q
C1I
2.7nH
2.7nH
2.7nH
2.7nH
2.7nH
LNQ
2.7nH
2.7nH
LPQ
2.7nH
LPI
LNI
LNQ
1.1nF
LPQ
1.1nF
LPI
LNI
1.1nF
1.1nF
C2Q
C2Q
C2I
C2I
RSLQ
RSLQ
100Ω
100Ω
100Ω
RSLI
100Ω
RSLI
23
24
19
20
23
24
19
20
QBBN
QBBP
IBBP
IBBN
QBBN
QBBP
IBBP
IBBN
F-MOD
F-MOD
Rev. 0 | Page 15 of 24
GSM OPERATION
Figure 34 shows the GSM EVM, spectral mask, and noise vs. the
output power for the ADL5372 at 1960 MHz. For a given LO
amplitude, the performance is independent of output power.
Figure 35 shows the GSM EVM and noise performance vs. the
LO amplitude at 1960 MHz with an output power of 5 dBm.
Increasing the LO drive level improves the noise performance
but degrades EVM performance.
Figure 35 illustrates that an LO amplitude of 3 dBm provides
the ideal operating point for noise and EVM for a GSM signal
at 1960 MHz.
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
Figure 35. GSM EVM and 6 MHz Noise Floor vs. LO Power at 1960 MHz;
Figure 34. GSM EVM and Spectral Performance vs. Channel Power at
0
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
–6
0
–6
RMS EVM
1960 MHz vs. Output Power; LO Power = 0 dBm
–4
–4
OUTPUT POWER (dBm)
–2
Output Power = 5 dBm
–2
LO DRIVE (dBm)
0
0
6 MHz NOISE FLOOR
6MHz NOISE FLOOR
PEAK EVM
RMS EVM
400kHz
600kHz
250kHz
1.2MHz
PEAK EVM
2
2
4
4
ADL5372
6
–30
–40
–50
–60
–70
–80
–90
–100
–110
6
–80
–85
–90
–95
–100
–105
–110
–115
–120