FUNCTIONAL BLOCK DIAGRAM
A/D DAC
CORRECTION LOGIC
OUTPUT BUFFERS
TIMING
CONTROL
THA THA THA
A/D DAC
A/D
26
23
27
214 24
65, 28 3, 25
20 19
AD773A
REFIN REFGND AGND DGND DRGND
AV
DD
AV
SS
DV
DD
DRV
DD
7, 22 8, 21
OTR
MSB
CLOCK
V
INA
V
INB
BIT 1
(MSB)
BIT 10
(LSB)
18 9
REV. 0
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a
10-Bit, 20 MSPS
Monolithic A/D Converter
AD773A
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 617/329-4700 Fax: 617/326-8703
PRODUCT DESCRIPTION
The AD773A is a monolithic 10-bit, 20 Msps analog-to-digital
converter incorporating an on-board, high performance track-
and-hold amplifier (THA). The AD773A converts video
bandwidth signals without the use of an external THA. The
AD773A implements a multistage differential pipelined
architecture with output error correction logic. The AD773A
offers accurate performance and guarantees no missing codes
over the full operating temperature range.
Output data is presented in binary and twos complement
format. An out of range (OTR) signal indicates the analog input
voltage is beyond the specified input range. OTR can be
decoded with the MSB/MSB pins to signal an underflow or
overflow condition. The high impedance reference input allows
multiple AD773As to be driven in parallel from a single
reference.
The combined dc precision and dynamic performance of the
AD773A is useful in a variety of applications. Typical
applications include: video enhancement, HDTV, ghost
cancellation, ultrasound imaging, radar and high speed data
acquisition.
The AD773A was designed using Analog Devices’ ABCMOS-1
process which utilizes high speed bipolar and 2-micron CMOS
transistors on a single chip. High speed, precision analog
circuits are now combined with high density logic circuits. Laser
trimmed thin film resistors are used to optimize accuracy and
temperature stability.
The AD773A is packaged in a 28-pin ceramic DIP and is
available in commercial (0°C to +70°C) and military (–55°C to
+125°C) grades.
FEATURES
Monolithic 10-Bit, 20 MSPS A/D Converter
Low Power Dissipation: 1.0 W
Signal-to-Noise Plus Distortion Ratio
f
IN
= 1 MHz: 56 dB
f
IN
= 10 MHz: 54 dB
Guaranteed No Missing Codes
On-Chip Track-and-Hold Amplifier
100 MHz Full Power Bandwidth
High Impedance Reference Input
Out of Range Output
Twos Complement and Binary Output Data
Available in Commercial and Military Temperature
Ranges (See Military/Aerospace Reference Manual
for Specifications)
PRODUCT HIGHLIGHTS
1. On-board THA
The high impedance differential input THA eliminates the
need for external buffering or sample and hold amplifiers.
The THA offers the choice of differential or single-ended
inputs. Input current is typically 5 µA.
2. High Impedance Reference Input
The high impedance reference input (200 kΩ) allows direct
connection with standard +2.5 V references, such as the
AD680, AD580 and REF43.
3. Output Data Flexibility
Output data is available in bipolar offset and bipolar twos
complement binary format.
4. Out of Range (OTR)
The OTR output bit indicates when the input signal is
beyond the AD773A’s input range.
5. Military Temperature Range