AD7885_15 Datasheet, PDF (1/16 Pages) Analog Devices – LC MOS 16-Bit, High Speed Sampling ADCs

a
LC²MOS
16-Bit, High Speed Sampling ADCs
AD7884/AD7885
FEATURES
Monolithic Construction
Fast Conversion: 5.3 ␮s
High Throughput Rate: 166 kSPS
Low Power: 250 mW
APPLICATIONS
Automatic Test Equipment
Medical Instrumentation
Industrial Control
Data Acquisition Systems
Robotics
GENERAL DESCRIPTION
The AD7884/AD7885 is a 16-bit monolithic analog-to-digital
converter with internal sample-and-hold and a conversion time
of 5.3 µs. The maximum throughput rate is 166 kSPS. It uses a
two-pass flash architecture to achieve this speed. Two input
ranges are available: ± 5 V and ± 3 V. Conversion is initiated by
the CONVST signal. The result can be read into a microprocessor
using the CS and RD inputs on the device. The AD7884 has a
16-bit parallel reading structure while the AD7885 has a byte reading
structure. The conversion result is in twos complement code.
The AD7884/AD7885 has its own internal oscillator that controls
conversion. It runs from ±5 V supplies and needs a V_REF+ of 3 V.
The AD7884 is available in a 40-lead CERDIP package and a
44-lead PLCC package.
The AD7885 is available in a 28-lead CERDIP package and the
AD7885A is available in a 44-lead PLCC package.
FUNCTIONAL BLOCK DIAGRAMS
؎3V_INF ؎3V_INS
AGNDS AGNDF AV_DD AV_SS VDD VSS
؎5V_INS
؎5V_INF
R2
3k⍀
R1
5k⍀
R3
3k⍀ C1
SW1 ^A1
AD7884
R6
2k⍀
R4
4k⍀
SW2
R5
4k⍀
V_REF–
A2
SW3
9-BIT
ADC
16-BIT
ACCURATE
DAC
9
TIMER
R7
2k⍀
9
9
LATCH
+ 16
ALU
O
U
T
P
U
T
D
R
I
V
E
R
S
16
DB15
DB0
CONTROL
CS
RD
R8
2k⍀
V_REF+F V_REF+S V_INV V_REF– GND CONVST BUSY DGND
؎3V_IN
AGNDS AGNDF AV_DD AV_SS VDD VSS
؎5V_INS
؎5V_INF
R2
3k⍀
R1
5k⍀
R3
3k⍀ C1
SW1 ^A1
AD7885
R6
2k⍀
R4
4k⍀
SW2
R5
4k⍀
V_REF–
A2
SW3
9-BIT
ADC
16-BIT
ACCURATE
DAC
9
TIMER
R7
2k⍀
9
9
LATCH
+ 16
ALU
O
U
T
P
U
T
D
R
I
V
E
R
S
8
DB7
DB0
CONTROL
CS
RD
R8
2k⍀
V_REF+F V_REF+S V_INV V_REF– GND CONVST BUSY DGND
HBEN
REV. E
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 that
may result from its use. No license is granted by implication or otherwise
under any patent or patent rights of Analog Devices. Trademarks and
registered trademarks are the property of their respective companies.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone]
www.analog.com
Fax: [phone] © 2003 Analog Devices, Inc. All rights reserved.