AD9708-EB Analog Devices Inc, AD9708-EB Datasheet

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AD9708-EB

Manufacturer Part Number
AD9708-EB
Description
BOARD EVAL FOR AD9708
Manufacturer
Analog Devices Inc
Series
TxDAC®r
Datasheets

Specifications of AD9708-EB

Rohs Status
RoHS non-compliant
Number Of Dac's
1
Number Of Bits
8
Outputs And Type
1, Differential
Sampling Rate (per Second)
125M
Data Interface
Parallel
Settling Time
35ns
Dac Type
Current
Voltage Supply Source
Analog and Digital
Operating Temperature
-40°C ~ 85°C
Utilized Ic / Part
AD9708
Lead Free Status / Rohs Status
Not Compliant
a
PRODUCT DESCRIPTION
The AD9708 is the 8-bit resolution member of the TxDAC
series of high performance, low power CMOS digital-to-analog
converters (DACs). The TxDAC family, which consists of pin
compatible 8-, 10-, 12-, and 14-bit DACs, was specifically opti-
mized for the transmit signal path of communication systems. All
of the devices share the same interface options, small outline
package and pinout, thus providing an upward or downward
component selection path based on performance, resolution and
cost. The AD9708 offers exceptional ac and dc performance
while supporting update rates up to 125 MSPS.
The AD9708’s flexible single-supply operating range of +2.7 V
to +5.5 V and low power dissipation are well suited for portable
and low power applications. Its power dissipation can be
further reduced to 45 mW, without a significant degradation in
performance, by lowering the full-scale current output. In addi-
tion, a power-down mode reduces the standby power dissipa-
tion to approximately 20 mW.
The AD9708 is manufactured on an advanced CMOS process.
A segmented current source architecture is combined with a
proprietary switching technique to reduce spurious components
and enhance dynamic performance. Edge-triggered input latches
and a temperature compensated bandgap reference have been inte-
grated to provide a complete monolithic DAC solution. Flexible
supply options support +3 V and +5 V CMOS logic families.
The AD9708 is a current-output DAC with a nominal full-scale
output current of 20 mA and > 100 k output impedance.
TxDAC is a registered trademark of Analog Devices, Inc.
REV. B
Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
FEATURES
Member of Pin-Compatible TxDAC Product Family
125 MSPS Update Rate
8-Bit Resolution
Linearity: 1/4 LSB DNL
Linearity:
Differential Current Outputs
SINAD @ 5 MHz Output: 50 dB
Power Dissipation: 175 mW @ 5 V to 45 mW @ 3 V
Power-Down Mode: 20 mW @ 5 V
On-Chip 1.20 V Reference
Single +5 V or +3 V Supply Operation
Packages: 28-Lead SOIC and 28-Lead TSSOP
Edge-Triggered Latches
Fast Settling: 35 ns Full-Scale Settling to 0.1%
APPLICATIONS
Communications
Signal Reconstruction
Instrumentation
1/4 LSB INL
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781/329-4700
Fax: 781/326-8703
Differential current outputs are provided to support single-
ended or differential applications. The current outputs may be
directly tied to an output resistor to provide two complemen-
tary, single-ended voltage outputs. The output voltage compliance
range is 1.25 V.
The AD9708 contains a 1.2 V on-chip reference and reference
control amplifier, which allows the full-scale output current to
be simply set by a single resistor. The AD9708 can be driven by
a variety of external reference voltages. The AD9708’s full-scale
current can be adjusted over a 2 mA to 20 mA range without
any degradation in dynamic performance. Thus, the AD9708
may operate at reduced power levels or be adjusted over a 20 dB
range to provide additional gain ranging capabilities.
The AD9708 is available in 28-lead SOIC and 28-lead TSSOP
packages. It is specified for operation over the industrial tem-
perature range.
PRODUCT HIGHLIGHTS
1. The AD9708 is a member of the TxDAC product family, which
2. Manufactured on a CMOS process, the AD9708 uses a pro-
3. On-chip, edge-triggered input CMOS latches readily interface
4. A flexible single-supply operating range of +2.7 V to +5.5 V
5. A temperature compensated, 1.20 V bandgap reference is
6. The current output(s) of the AD9708 can easily be config-
provides an upward or downward component selection path
based on resolution (8 to 14 bits), performance and cost.
prietary switching technique that enhances dynamic perfor-
mance well beyond 8- and 10-bit video DACs.
to +3 V and +5 V CMOS logic families. The AD9708 can
support update rates up to 125 MSPS.
and a wide full-scale current adjustment span of 2 mA to
20 mA allows the AD9708 to operate at reduced power levels
(i.e., 45 mW) without any degradation in dynamic performance.
included on-chip providing a complete DAC solution. An
external reference may be used.
ured for various single-ended or differential applications.
CLOCK
R
SET
+5V
0.1 F
FUNCTIONAL BLOCK DIAGRAM
REF IO
FS ADJ
CLOCK
DVDD
DCOM
+1.20V REF
TxDAC
SLEEP
REFLO
World Wide Web Site: http://www.analog.com
COMP1
DIGITAL DATA INPUTS (DB7–DB0)
8-Bit, 100 MSPS+
50pF
®
0.1 F
D/A Converter
CURRENT
SEGMENTED
SOURCE
SWITCHES
ARRAY
LATCHES
© Analog Devices, Inc., 1999
+5V
AVDD
AD9708
AD9708
ACOM
COMP2
IOUTA
IOUTB
0.1 F

Related parts for AD9708-EB

AD9708-EB Summary of contents

Page 1

... The AD9708 contains a 1.2 V on-chip reference and reference control amplifier, which allows the full-scale output current to be simply set by a single resistor. The AD9708 can be driven by a variety of external reference voltages. The AD9708’s full-scale current can be adjusted over range without any degradation in dynamic performance ...

Page 2

... AD9708–SPECIFICATIONS DC SPECIFICATIONS ( MIN Parameter RESOLUTION MONOTONICITY 1 DC ACCURACY Integral Linearity Error (INL) Differential Nonlinearity (DNL) ANALOG OUTPUT Offset Error Gain Error (Without Internal Reference) Gain Error (With Internal Reference) 2 Full-Scale Output Current Output Compliance Range Output Resistance Output Capacitance REFERENCE OUTPUT ...

Page 3

... Single-Ended Output, IOUTA, 50 OUTFS Typ Max 125 2.5 2 –67 –67 –62 –59 –64 – unless otherwise noted) OUTFS Typ Max 1.3 0 0.9 +10 +10 5 0.1% AD9708 Doubly Units MSPS pA dBc dBc dBc dBc dBc dBc dBc dBc dBc dBc Units ...

Page 4

... ACOM COMP1 FS ADJ Model REFIO REFLO AD9708AR SLEEP AD9708ARU – +85 C 28-Lead TSSOP AD9708- Small Outline IC Thin Small Outline IC. –4– PIN FUNCTION DESCRIPTIONS Description DB7 Most Significant Data Bit (MSB). DB6–DB1 Data Bits 1–6. DB0 Least Significant Data Bit (LSB). ...

Page 5

... FS ADJ ARRAY DVDD SEGMENTED DCOM SWITCHES CLOCK LATCHES SLEEP DIGITAL DATA CLOCK OUTPUT TEKTRONIX AWG-2021 Figure 2. Basic AC Characterization Test Setup –5– AD9708 COMP2 0.1 F IOUTA TO HP3589A IOUTB SPECTRUM/ NETWORK ANALYZER 50 20pF 50 INPUT 20pF 50 * AWG2021 CLOCK RETIMED SUCH THAT DIGITAL DATA TRANSITIONS ON FALLING EDGE OF 50% DUTY CYCLE CLOCK ...

Page 6

... AD9708 Typical AC Characterization Curves Single-Ended Output mA, T OUTA OUTFS A 70 THD @ 50MSPS THD @ 10MSPS 65 THD @ 100MSPS SINAD @ 10MSPS SINAD @ 50MSPS 45 SINAD @ 100MSPS 40 0 100 FREQUENCY – MHz Figure 3. SINAD/THD vs. f (AVDD OUT and DVDD = 5 THD @ 10MSPS 65 THD @ 100MSPS 60 THD @ 50MSPS 55 50 ...

Page 7

... FUNCTIONAL DESCRIPTION Figure 12 shows a simplified block diagram of the AD9708. The AD9708 consists of a large PMOS current source array capable of providing total current. The array is divided into 31 equal currents that make up the five most significant bits (MSBs). The remaining 3 LSBs are also implemented with equally weighted current sources whose sum total equals 7/8th of an MSB current source ...

Page 8

... A and 625 A. The wide adjustment span of REF I provides several application benefits. The first benefit OUTFS relates directly to the power dissipation of the AD9708, which is proportional to I (refer to the POWER DISSIPATION OUTFS section). The second benefit relates to the 20 dB adjustment, which is useful for system gain control purposes. ...

Page 9

... TTL drivers. A DVDD 3.3 V will typically ensure upper compatibility of most TTL logic families. OUTFS Since the AD9708 is capable of being updated up to 125 MSPS, the quality of the clock and data input signals are important in achieving the optimum performance. The drivers of the digital ...

Page 10

... Proper RF techniques must be used in device selection placement and routing and supply bypassing and grounding. The evaluation board for the AD9708, which uses a four layer PC board, serves as a good example for the above mentioned considerations. The evaluation board provides an illustration of the recommended printed circuit board ground, power and signal plane layouts ...

Page 11

... LOAD AD9708 EVALUATION BOARD General Description DIFF The AD9708- evaluation board for the AD9708 8-bit D/A converter. Careful attention to layout and circuit design, combined with a prototyping area, allows the user to easily and effectively evaluate the AD9708 in any application where high resolution, high speed conversion is required. ...

Page 12

... AD9708 Figure 26. Evaluation Board Schematic –12– REV. B ...

Page 13

... REV. B Figure 27. Silkscreen Layer—Top Figure 28. Component Side PCB Layout (Layer 1) –13– AD9708 ...

Page 14

... AD9708 Figure 29. Ground Plane PCB Layout (Layer 2) Figure 30. Power Plane PCB Layout (Layer 3) –14– REV. B ...

Page 15

... REV. B Figure 31. Solder Side PCB Layout (Layer 4) Figure 32. Silkscreen Layer—Bottom –15– AD9708 ...

Page 16

... AD9708 PIN 1 0.0118 (0.30) 0.0040 (0.10) 0.006 (0.15) 0.002 (0.05) SEATING PLANE OUTLINE DIMENSIONS Dimensions shown in inches and (mm). 28-Lead, 300 Mil SOIC (R-28) 0.7125 (18.10) 0.6969 (17.70 0.2992 (7.60) 0.2914 (7.40) 0.4193 (10.65 0.3937 (10.00) 0.1043 (2.65) 0.0926 (2.35) 0.0500 0.0192 (0.49) SEATING 0 ...

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