a
FEATURES
Ultrahigh Speed: Current Settling to 1 LSB in 35 ns
High Stability Buried Zener Reference on Chip
Monotonicity Guaranteed Over Temperature
10.24 mA Full-Scale Output Suitable for Video
Applications
Integral and Differential Linearity Guaranteed Over
Temperature
0.3" 鈥淪kinny DIP鈥?Packaging
Variable Threshold Allows TTL and CMOS
Interface
MIL-STD-883 Compliant Versions Available
12-Bit Ultrahigh Speed
Monolithic D/A Converter
AD568
FUNCTIONAL BLOCK DIAGRAM
PRODUCT DESCRIPTION
The AD568 is an ultrahigh-speed, 12-bit digital-to-analog con-
verter (DAC) settling to 0.025% in 35 ns. The monolithic de-
vice is fabricated using Analog Devices鈥?Complementary Bipolar
(CB) Process. This is a proprietary process featuring high-speed
NPN and PNP devices on the same chip without the use of di-
electric isolation or multichip hybrid techniques. The high speed
of the AD568 is maintained by keeping impedance levels low
enough to minimize the effects of parasitic circuit capacitances.
The DAC consists of 16 current sources configured to deliver a
10.24 mA full-scale current. Multiple matched current sources
and thin-film ladder techniques are combined to produce bit
weighting. The DAC鈥檚 output is a 10.24 mA full scale (FS) for
current output applications or a 1.024 V FS unbuffered voltage
output. Additionally, a 10.24 V FS buffered output may be gen-
erated using an onboard 1 k鈩?span resistor with an external op
amp. Bipolar ranges are accomplished by pin strapping.
Laser wafer trimming insures full 12-bit linearity. All grades of
the AD568 are guaranteed monotonic over their full operating
temperature range. Furthermore, the output resistance of the
DAC is trimmed to 100
鈩?鹵
1.0%. The gain temperature coeffi-
cient of the voltage output is 30 ppm/擄C max (K).
The AD568 is available in three performance grades. The
AD568JQ and KQ are available in 24-pin cerdip (0.3") packages
and are specified for operation from 0擄C to +70擄C. The
AD568SQ features operation from 鈥?5擄C to +125擄C and is also
packaged in the hermetic 0.3" cerdip.
PRODUCT HIGHLIGHTS
1. The ultrafast settling time of the AD568 allows leading edge
performance in waveform generation, graphics display and
high speed A/D conversion applications.
2. Pin strapping provides a variety of voltage and current output
ranges for application versatility. Tight control of the abso-
lute output current reduces trim requirements in externally-
scaled applications.
3. Matched on-chip resistors can be used for precision scaling in
high speed A/D conversion circuits.
4. The digital inputs are compatible with TTL and +5 V
CMOS logic families.
5. Skinny DIP (0.3") packaging minimizes board space require-
ments and eases layout considerations.
6. The AD568 is available in versions compliant with MIL-
STD-883. Refer to the Analog Devices Military Products
Databook or current AD568/883B data sheet for detailed
specifications.
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.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 617/329-4700
Fax: 617/326-8703
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