
REV. A
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.
a
AD9720/AD9721
FEATURES
400 MSPS (ECL)/100 MSPS (TTL) Update Rate
Low Glitch Impulse: 1.5 pV-s
Fast Settling: 4.5 ns to 1/2 LSB
Low Power: 1.1 W
On-Board Quadrature Logic for DDS Applications
Differential Clock (ECL)
APPLICATIONS
Direct Digital Synthesis
Arbitrary Waveform Synthesis
Waveform Reconstruction
High Speed Imaging
10-Bit, 400 MSPS
D/AConverters
isolated bipolar process. T he AD9720 is ECL compatible, and
will update up to 400 MSPS; the AD9721 is T T L compatible
and will update up to 100 MSPS.
Designed for direct digital synthesis (DDS), waveform recon-
struction, and high resolution video applications, both devices
feature low glitch impulse of 1.5 pV-s and fast settling times of
4.5 ns to 1/2 LSB.
Both converters are characterized for dynamic performance, and
have excellent harmonic suppression and spectral purity in
waveform generation applications.
T he units are available in 28-lead DIPs, L CCs and SOICs.
Industrial temperature range devices are packaged in plastic for
operation from –25
°
C to +25
°
C; extended temperature range
devices for operation from –55
°
C to +125
°
C are in hermetic
ceramic packages. Contact the factory for information about the
availability of MIL-ST D-883 devices.
GE NE RAL DE SCRIPT ION
T he AD9720 and AD9721 D/A converters are 10-bit, high
speed digital-to-analog converters constructed in an oxide
FUNCT IONAL BLOCK DIAGRAM
I
10
CONTROL
AMP
–
+
INTERNAL
VOLTAGE
REFERENCE
REFERENCE
OUT
CONTROL
AMP IN
R
SET
REFERENCE
IN
CONTROL
AMP OUT
S
N
R
D
D
D
1
CLOCK
INVERT
CLOCK
TTL
OR
ECL
DRIVE
LOGIC
I
OUT
ANALOG
RETURN
BYP.
ANALOG
–V
S
–5.2V
BYP.
DIGITAL
+V
S
+5V
BYP.
–5.2V
DIGITAL
–V
S
0.1
μ
F
I
OUT
D
2
D
10
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 617/329-4700
World Wide Web Site: http://www.analog.com
Fax: 617/326-8703
Analog Devices, Inc., 1997