AD9740ACP-PCBZ Analog Devices Inc, AD9740ACP-PCBZ Datasheet - Page 17

• Manufacturer Part Number: AD9740ACP-PCBZ
• Description: Eval Board 10 BIT 210 MSPS TxDAC DAC IC
• Manufacturer: Analog Devices Inc
• Series: TxDAC®r

Specifications of AD9740ACP-PCBZ

• Number Of Dac's: 1
• Number Of Bits: 10
• Outputs And Type: 1, Differential
• Sampling Rate (per Second): 210M
• Data Interface: Parallel
• Settling Time: 11ns
• Dac Type: Current
• Voltage Supply Source: Analog and Digital
• Operating Temperature: -40°C ~ 85°C
• Utilized Ic / Part: AD9740
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

35
30
25
20
15
10
11
10
20
18
16
14
12
10
0
9
8
7
6
5
4
3
2
1
0
8
6
4
2
0
0.01
2
0
4
Figure 31. I
Figure 30. I
50
6
Figure 29. I
CLKVDD
DVDD
8
RATIO (f
100
f
vs. Ratio @ DVDD = 3.3 V
CLOCK
vs. f
I
210MSPS
165MSPS
125MSPS
OUTFS
10
65MSPS
AVDD
DIFF
CLOCK
0.1
OUT
PECL
(MSPS)
(mA)
SE
/f
12
vs. I
CLOCK
and Clock Mode
150
OUTFS
14
)
16
200
18
250
20
1
Rev. B | Page 17 of 32
APPLYING THE AD9740
Output Configurations
The following sections illustrate some typical output
configurations for the AD9740. Unless otherwise noted, it is
assumed that I
requiring the optimum dynamic performance, a differential
output configuration is suggested. A differential output
configuration can consist of either an RF transformer or a
differential op amp configuration. The transformer
configuration provides the optimum high frequency
performance and is recommended for any application that
allows ac coupling. The differential op amp configuration is
suitable for applications requiring dc coupling, bipolar output,
signal gain, and/or level shifting within the bandwidth of the
chosen op amp.
A single-ended output is suitable for applications requiring a
unipolar voltage output. A positive unipolar output voltage
results if IOUTA and/or IOUTB is connected to an
appropriately sized load resistor, R
This configuration can be more suitable for a single-supply
system requiring a dc-coupled, ground referred output voltage.
Alternatively, an amplifier could be configured as an I-V
converter, thus converting IOUTA or IOUTB into a negative
unipolar voltage. This configuration provides the best dc linearity
because IOUTA or IOUTB is maintained at a virtual ground.
DIFFERENTIAL COUPLING USING A TRANSFORMER
An RF transformer can be used to perform a differential-to-
single-ended signal conversion, as shown in Figure 32. A
differentially coupled transformer output provides the
optimum distortion performance for output signals whose
spectral content lies within the transformer’s pass band. An
RF transformer, such as the Mini-Circuits® T1–1T, provides
excellent rejection of common-mode distortion (that is, even-
order harmonics) and noise over a wide frequency range. It also
provides electrical isolation and the ability to deliver twice the
power to the load. Transformers with different impedance ratios
can also be used for impedance matching purposes. Note that
the transformer provides ac coupling only.
AD9740
Figure 32. Differential Output Using a Transformer
IOUTA
IOUTB
OUTFS
is set to a nominal 20 mA. For applications
22
21
OPTIONAL R
MINI-CIRCUITS
LOAD
T1-1T
, referred to ACOM.
DIFF
R
AD9740
LOAD