REV.0
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a
AD9218
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781/329-4700 www.analog.com
Fax: 781/326-8703 © Analog Devices, Inc., 2001
FUNCTIONAL BLOCK DIAGRAM
10-Bit, 40/65/80/105 MSPS
3 V Dual A/D Converter
TIMING
ADC
OUTPUT
REGISTER
REF
T/H
10 10
ADC
OUTPUT
REGISTER
T/H
10 10
TIMING
USER
SELECT #1
USER
SELECT #2
DATA
FORMAT/
GAIN
D
9B
–D
0B
D
9A
–D
0A
V
DD
GNDV
D
AD9218ENCODE A
ENCODE B
A
IN
B
A
IN
A
A
IN
A
REF
IN
A
REF
IN
B
REF
OUT
A
IN
B
FEATURES
Dual 10-Bit, 40 MSPS, 65 MSPS, 80 MSPS, and
105MSPS ADC
Low Power: 275 mW at 105 MSPS per Channel
On-Chip Reference and Track/Holds
300 MHz Analog Bandwidth Each Channel
SNR = 57 dB @ 41 MHz, Encode = 80 MSPS
1 V p-p or 2 V p-p Analog Input Range Each Channel
Single 3.0 V Supply Operation (2.7 V–3.6 V)
Power-Down Mode for Single Channel Operation
Two’s Complement or Offset Binary Output Mode
Output Data Alignment Mode
Pin-Compatible with 8-Bit AD9288
–75 dBc Crosstalk between Channels
APPLICATIONS
Battery-Powered Instruments
Hand-Held Scopemeters
Low Cost Digital Oscilloscopes
I and Q Communications
Ultrasound Equipment
GENERAL DESCRIPTION
The AD9218 is a dual 10-bit monolithic sampling analog-to-
digital converter with on-chip track-and-hold circuits and is
optimized for low cost, low power, small size and ease of use.
The product operates at a 105 MSPS conversion rate with
outstanding dynamic performance over its full operating range.
Each channel can be operated independently.
The ADC requires only a single 3.0 V (2.7 V to 3.6 V) power
supply and an encode clock for full operation. No external
reference or driver components are required for many applica-
tions. The digital outputs are TTL/CMOS-compatible and a
separate output power supply pin supports interfacing with
3.3 V or 2.5 V logic.
The clock input is TTL/CMOS-compatible and the 10-bit
digital outputs can be operated from 3.0 V (2.5 V to 3.6 V)
supplies. User-selectable options are available to offer a combi-
nation of power-down modes, digital data formats and digital
data timing schemes. In power-down mode, the digital outputs
are driven to a high-impedance state.
Fabricated on an advanced CMOS process, the AD9218 is
available in a 48-lead surface-mount plastic package (7 × 7 mm
LQFP) specified over the industrial temperature range (–40°C
to +85°C).
PRODUCT HIGHLIGHTS
Low Power—Just 275 mW power dissipation per channel at
105 MSPS. Other speed grade proportionally scaled down while
maintaining high ac performance.
Pin Compatibility Upgrade—Allows easy migration from 8-bit
to 10-bit. Pin-compatible with the 8-bit AD9288 dual ADC.
Ease of Use—On-chip reference and user controls provide flex-
ibility in system design.
High Performance—Maintain 54 dB SNR at 105 MSPS with a
Nyquist input.
Channel Crosstalk—Very low at –75 dBc.