a
FEATURES
CMOS 8-Bit 32 MSPS Sampling A/D Converter
Pin-Compatible with AD876-8
Power Dissipation: 95 mW (3 V Supply)
Operation Between +2.7 V and +5.5 V Supply
Differential Nonlinearity: 0.2 LSB
Power-Down (Sleep) Mode
Three-State Outputs
Out-of-Range Indicator
Built-In Clamp Function (DC Restore)
Adjustable On-Chip Voltage Reference
IF Undersampling to 135 MHz
PRODUCT DESCRIPTION
Complete 8-Bit, 32 MSPS, 95 mW
CMOS A/D Converter
AD9280
A single clock input is used to control all internal conversion
cycles. The digital output data is presented in straight binary
output format. An out-of-range signal (OTR) indicates an over-
flow condition which can be used with the most significant bit
to determine low or high overflow.
The AD9280 can operate with a supply range from +2.7 V to
+5.5 V, ideally suiting it for low power operation in high speed
applications.
The AD9280 is specified over the industrial (–40°C to +85°C)
temperature range.
PRODUCT HIGHLIGHTS
Low Power
The AD9280 is a monolithic, single supply, 8-bit, 32 MSPS
analog-to-digital converter with an on-chip sample-and-hold
amplifier and voltage reference. The AD9280 uses a multistage
differential pipeline architecture at 32 MSPS data rates and
guarantees no missing codes over the full operating temperature
range.
The input of the AD9280 has been designed to ease the devel-
opment of both imaging and communications systems. The user
can select a variety of input ranges and offsets and can drive the
input either single-ended or differentially.
The sample-and-hold amplifier (SHA) is equally suited for both
multiplexed systems that switch full-scale voltage levels in suc-
cessive channels and sampling single-channel inputs at frequen-
cies up to and beyond the Nyquist rate. AC-coupled input
signals can be shifted to a predetermined level, with an onboard
clamp circuit. The dynamic performance is excellent.
The AD9280 has an onboard programmable reference. An
external reference can also be chosen to suit the dc accuracy and
temperature drift requirements of the application.
The AD9280 consumes 95 mW on a 3 V supply (excluding the
reference power). In sleep mode, power is reduced to below
5 mW.
Very Small Package
The AD9280 is available in a 28-lead SSOP package.
Pin Compatible with AD876-8
The AD9280 is pin compatible with the AD876-8, allowing
older designs to migrate to lower supply voltages.
300 MHz Onboard Sample-and-Hold
The versatile SHA input can be configured for either single-
ended or differential inputs.
Out-of-Range Indicator
The OTR output bit indicates when the input signal is beyond
the AD9280’s input range.
Built-In Clamp Function
Allows dc restoration of video signals.
FUNCTIONAL BLOCK DIAGRAM
CLAMP
CLAMP
IN
CLK
AVDD
DRVDD
STBY
SHA
VINA
REFTF
REFTS
REFBS
REFBF
OUTPUT BUFFERS
VREF
REFSENSE
1V
A/D
D/A
A/D
D/A
A/D
D/A
A/D
D/A
SHA
GAIN
SHA
GAIN
SHA
GAIN
SHA
GAIN
A/D
MODE
THREE-
STATE
CORRECTION LOGIC
OTR
D7 (MSB)
D0 (LSB)
AVSS
DRVSS
AD9280
REV. D
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: 781/329-4700
World Wide Web Site: http://www.analog.com
Fax: 781/326-8703
© Analog Devices, Inc., 1999
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