AD9762ARUZ Analog Devices Inc, AD9762ARUZ Datasheet - Page 15

• Manufacturer Part Number: AD9762ARUZ
• Description: IC DAC 12BIT 125MSPS 28-TSSOP
• Manufacturer: Analog Devices Inc
• Series: TxDAC®r

Specifications of AD9762ARUZ

• Data Interface: Parallel
• Settling Time: 35ns
• Number Of Bits: 12
• Number Of Converters: 1
• Voltage Supply Source: Analog and Digital
• Power Dissipation (max): 160mW
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 28-TSSOP
• Resolution (bits): 12bit
• Sampling Rate: 125MSPS
• Input Channel Type: Parallel
• Supply Voltage Range - Analog: 2.7V To 5.5V
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: AD9762-EB - BOARD EVAL FOR AD9762
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

Conversely, I
form, f
show I
(f
DVDD = 3 V, respectively. Note, how I
than a factor of 2 when DVDD is reduced from 5 V to 3 V.
REV. B
OUT
/f
DVDD
CLOCK
CLOCK
30
25
20
15
10
5
0
18
16
14
12
10
8
6
4
2
0
0.01
0.01
Figure 48. I
Figure 49. I
8
6
4
2
0
2
as a function of full-scale sine wave output ratios
) for various update rates with DVDD = 5 V and
, and digital supply DVDD. Figures 48 and 49
DVDD
4
Figure 47. I
is dependent on both the digital input wave-
6
DVDD
DVDD
8
RATIO (f
RATIO (f
vs. Ratio @ DVDD = 5 V
vs. Ratio @ DVDD = 3 V
I
OUTFS
10
AVDD
0.1
0.1
OUT
OUT
– mA
12
/f
vs. I
/f
CLK
CLK
DVDD
)
14
)
OUTFS
is reduced by more
16
125MSPS
100MSPS
50MSPS
25MSPS
5MSPS
125MSPS
100MSPS
50MSPS
25MSPS
5MSPS
18
20
1
1
–15–
APPLYING THE AD9762
OUTPUT CONFIGURATIONS
The following sections illustrate some typical output configura-
tions for the AD9762. Unless otherwise noted, it is assumed
that I
ing the optimum dynamic performance, a differential output
configuration is suggested. A differential output configuration
may 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 allowing for ac coupling. The differential op
amp configuration is suitable for applications requiring dc
coupling, a bipolar output, signal gain and/or level shifting.
A single-ended output is suitable for applications requiring a
unipolar voltage output. A positive unipolar output voltage will
result if I
sized load resistor, R
tion may 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
I
tion provides the best dc linearity since I
maintained at a virtual ground. Note, I
better performance than I
DIFFERENTIAL COUPLING USING A TRANSFORMER
An RF transformer can be used to perform a differential-to-
single-ended signal conversion as shown in Figure 50. A
differentially coupled transformer output provides the optimum
distortion performance for output signals whose spectral content
lies within the transformer’s passband. An RF transformer such
as the Mini-Circuits T1-1T provides excellent rejection of
common-mode distortion (i.e., 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. Trans-
formers with different impedance ratios may also be used for
impedance matching purposes. Note that the transformer
provides ac coupling only.
The center tap on the primary side of the transformer must be
connected to ACOM to provide the necessary dc current path
for both I
ing at I
cally around ACOM and should be maintained with the specified
output compliance range of the AD9762. A differential resistor,
R
the transformer is connected to the load, R
reconstruction filter or cable. R
transformer’s impedance ratio and provides the proper source
termination which results in a low VSWR. Note that approxi-
mately half the signal power will be dissipated across R
OUTA
DIFF
Figure 50. Differential Output Using a Transformer
OUTFS
, may be inserted in applications in which the output of
or I
OUTA
OUTA
OUTA
OUTB
is set to a nominal 20 mA. For applications requir-
and I
AD9762
and I
and/or I
into a negative unipolar voltage. This configura-
IOUTA
IOUTB
OUTB
OUTB
LOAD
22
21
(i.e., V
OUTB
. The complementary voltages appear-
, referred to ACOM. This configura-
OUTB
is connected to an appropriately
OPTIONAL R
OUTA
.
MINI-CIRCUITS
DIFF
and V
T1-1T
is determined by the
DIFF
OUTA
OUTB
OUTA
LOAD
provides slightly
) swing symmetri-
, via a passive
AD9762
or I
R
LOAD
OUTB
DIFF
is
.