Complete 12-Bit, 40 MSPS
Monolithic A/D Converter
a
AD9224
FUNCTIONAL BLOCK DIAGRAM
FEATURES
Monolithic 12-Bit, 40 MSPS A/D Converter
Low Power Dissipation: 415 mW
Single +5 V Supply
No Missing Codes Guaranteed
Differential Nonlinearity Error: ؎0.33 LSB
Complete On-Chip Sample-and-Hold Amplifier and
Voltage Reference
DRVDD
AVDD
CLK
SHA
VINA
VINB
MDAC1
GAIN = 16
MDAC2
GAIN = 4
MDAC3
GAIN = 4
5
3
3
A/D
A/D
A/D
A/D
CML
CAPT
CAPB
5
3
4
3
DIGITAL CORRECTION LOGIC
Signal-to-Noise and Distortion Ratio: 68.3 dB
Spurious-Free Dynamic Range: 81 dB
Out-of-Range Indicator
Straight Binary Output Data
28-Lead SSOP Package
12
VREF
OUTPUT BUFFERS
OTR
SENSE
BIT 1
(MSB)
1V
MODE
SELECT
BIT 12
(LSB)
AD9224
DRVSS
REFCOM
AVSS
Compatible with 3 V Logic
PRODUCT DESCRIPTION
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 indicates an overflow
condition which can be used with the most significant bit to
determine low or high overflow.
The AD9224 is a monolithic, single supply, 12-bit, 40 MSPS,
analog-to-digital converter with an on-chip, high performance
sample-and-hold amplifier and voltage reference. The AD9224
uses a multistage differential pipelined architecture with output
error correction logic to provide 12-bit accuracy at 40 MSPS
data rates, and guarantees no missing codes over the full operat-
ing temperature range.
PRODUCT HIGHLIGHTS
The AD9224 is fabricated on a very cost effective CMOS
process. High speed precision analog circuits are now combined
with high density logic circuits.
The AD9224 combines a low cost high speed CMOS process
and a novel architecture to achieve the resolution and speed of
existing bipolar implementations at a fraction of the power
consumption and cost.
The AD9224 offers a complete single-chip sampling 12-bit,
40 MSPS analog-to-digital conversion function in 28-lead
SSOP package.
The input of the AD9224 allows for easy interfacing to both
imaging and communications systems. With a truly differential
input structure, the user can select a variety of input ranges and
offsets, including single-ended applications. The dynamic per-
formance is excellent.
Low Power—The AD9224 at 415 mW consumes a fraction of
the power of presently available in existing monolithic solutions.
On-Board Sample-and-Hold (SHA)—The versatile SHA
input can be configured for either single-ended or differential
inputs.
The sample-and-hold (SHA) amplifier is well 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 well beyond the Nyquist rate.
Out of Range (OTR)—The OTR output bit indicates when
the input signal is beyond the AD9224’s input range.
Single Supply—The AD9224 uses a single +5 V power supply
simplifying system power supply design. It also features a sepa-
rate digital driver supply line to accommodate 3 V and 5 V logic
families.
The AD9224’s wideband input, combined with the power and
cost savings over previously available monolithics, is suitable for
applications in communications, imaging and medical ultrasound.
The AD9224 has an onboard programmable reference. An
external reference can also be chosen to suit the dc accuracy
and temperature drift requirements of the application.
Pin Compatibility—The AD9224 is pin compatible with the
AD9220, AD9221, AD9223 and AD9225 ADCs.
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.
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© Analog Devices, Inc., 1999