AD9022 Datasheet, PDF (1/12 Pages) Analog Devices – 12-Bit 20 MSPS Monolithic A/D Converter

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FEATURES
Monolithic
12-Bit 20 MSPS A/D Converter
Low Power Dissipation: 1.4 Watts
On-Chip T/H and Reference
High Spurious-Free Dynamic Range
TTL Logic
APPLICATIONS
Radar Receivers
Digital Communications
Digital Instrumentation
Electro-Optics
12-Bit 20 MSPS
Monolithic A/D Converter
AD9022
FUNCTIONAL BLOCK DIAGRAM
ANALOG
T/H
INPUT
ENCODE
5-BIT
ADC
DAC
AD9022
5-BIT
ADC
DIGITAL 12
ERROR
CORRECTION TTL
T/H 16
+2V
REF
DAC
8
4-BIT
ADC
+5V
–5.2V
GND
PRODUCT DESCRIPTION
The AD9022 is a high speed, high performance, monolithic
12-bit analog-to-digital converter. All necessary functions, in-
cluding track-and-hold (T/H) and reference, are included
on-chip to provide a complete conversion solution. It is a
companion unit to the AD9023; the primary difference between
the two is that all logic for the AD9022 is TTL-compatible,
while the AD9023 utilizes ECL logic for digital inputs and out-
puts. Pinouts for the two parts are nearly identical.
Operating from +5 V and –5.2 V supplies, the AD9022 pro-
vides excellent dynamic performance. Sampling at 20 MSPS
with A_IN = 1 MHz, the spurious-free dynamic range (SFDR) is
typically 76 dB; with A_IN = 9.6 MHz, SFDR is 74 dB. SNR is
typically 65 dB.
The onboard T/H has a 110 MHz bandwidth and, more impor-
tantly, is designed to provide excellent dynamic performance for
analog input frequencies above Nyquist. This feature is neces-
sary in many undersampling signal processing applications, such
as in direct IF-to-digital conversion.
To maintain dynamic performance at higher IFs, monolithic
RF track-and-holds (such as the AD9100 and AD9101
Samplifier™) can be used with the AD9022 to process signals
up to and beyond 70 MHz.
With DNL typically less than 0.5 LSB and 20 ns transient re-
sponse settling time, the AD9022 provides excellent results
when low-frequency analog inputs must be oversampled (such
as CCD digitization). The full scale analog input is ± 1 V with a
300 Ω input impedance. The analog input can be driven directly
from the signal source, or can be buffered by the AD96xx series
of low noise, low distortion buffer amplifiers.
All timing is internal to the AD9022; the clock signal initiates
the conversion cycle. For best results, the encode command
should contain as little jitter as possible. High speed layout
practices must be followed to ensure optimum A/D perfor-
mance.
The AD9022 is built on a trench isolated bipolar process and
utilizes an innovative multipass architecture (see the block
diagram). The unit is packaged in 28-lead ceramic DIPs and
gullwing surface mount packages. The AD9022 is specified to
operate over the industrial (–25°C to +85°C) and military
(–55°C to +125°C) temperature ranges.
Samplifier is a 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.
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© Analog Devices, Inc., 1998