AD9742ACPZ Datasheet, PDF (1/32 Pages) Analog Devices – 12-Bit, 210 MSPS TxDAC Digital-to-Analog Converter

Data Sheet
12-Bit, 210 MSPS
TxDAC Digital-to-Analog Converter
AD9742
FEATURES
High performance member of pin-compatible TxDAC
product family
Excellent spurious-free dynamic range performance
SNR at 5 MHz output, 125 MSPS: 70 dB
Twos complement or straight binary data format
Differential current outputs: 2 mA to 20 mA
Power dissipation: 135 mW at 3.3 V
Power-down mode: 15 mW at 3.3 V
On-chip 1.2 V Reference
CMOS compatible digital interface
28-lead SOIC, 28-lead TSSOP, and 32-lead LFCSP
Edge-triggered latches
APPLICATIONS
Wideband communication transmit channel:
Direct IF
Base stations
Wireless local loops
Digital radio links
Direct digital synthesis (DDS)
Instrumentation
GENERAL DESCRIPTION
The AD9742¹ is a 12-bit resolution, wideband, third generation
member of the TxDAC series of high performance, low power
CMOS digital-to-analog converters (DACs). The TxDAC family,
consisting of pin-compatible 8-, 10-, 12-, and 14-bit DACs,
is specifically optimized for the transmit signal path of
communication systems. All of the devices share the same interface
options, small outline package, and pinout, providing an upward
or downward component selection path based on performance,
resolution, and cost. The AD9742 offers exceptional ac and dc
performance while supporting update rates up to 210 MSPS.
The AD9742’s low power dissipation makes it well suited for
portable and low power applications. Its power dissipation can
be further reduced to a mere 60 mW with a slight degradation
in performance by lowering the full-scale current output. Also,
a power-down mode reduces the standby power dissipation to
approximately 15 mW. A segmented current source architecture
is combined with a proprietary switching technique to reduce
spurious components and enhance dynamic performance.
1 _{Protected by U.S. Patent Numbers: 5,568,145; 5,689,257; and 5,703,519.}
FUNCTIONAL BLOCK DIAGRAM
3.3V
0.1µF
R_{SET 3.3V}
CLOCK
REFLO
1.2V REF
REFIO
FS ADJ
150pF
AVDD ACOM
CURRENT ^AD9742
SOURCE
ARRAY
DVDD
DCOM
SEGMENTED
SWITCHES
LSB
SWITCHES
IOUTA
IOUTB
CLOCK
LATCHES
MODE
SLEEP
DIGITAL DATA INPUTS (DB11–DB0)
Figure 1.
Edge-triggered input latches and a 1.2 V temperature compensated
band gap reference have been integrated to provide a complete
monolithic DAC solution. The digital inputs support 3 V CMOS
logic families.
PRODUCT HIGHLIGHTS
1. The AD9742 is the 12-bit member of the pin-compatible
TxDAC family, which offers excellent INL and DNL
performance.
2. Data input supports twos complement or straight binary
data coding.
3. High speed, single-ended CMOS clock input supports
210 MSPS conversion rate.
4. Low power: Complete CMOS DAC function operates on
135 mW from a 2.7 V to 3.6 V single supply. The DAC full-
scale current can be reduced for lower power operation,
and a sleep mode is provided for low power idle periods.
5. On-chip voltage reference: The AD9742 includes a 1.2 V
temperature compensated band gap voltage reference.
6. Industry-standard 28-lead SOIC, 28-lead TSSOP, and
32-lead LFCSP packages.
Rev. C
Document Feedback
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 that may result from its use. Specifications subject to change without notice. No
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
Trademarks and registered trademarks are the property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone] ©2002–2013 Analog Devices, Inc. All rights reserved.
Technical Support
www.analog.com