欢迎访问ic37.com |
会员登录 免费注册
发布采购

AD7891AS-1 参数 Datasheet PDF下载

AD7891AS-1图片预览
型号: AD7891AS-1
PDF下载: 下载PDF文件 查看货源
内容描述: LC2MOS 8通道, 12位高速数据采集系统 [LC2MOS 8-Channel, 12-Bit High Speed Data Acquisition System]
分类和应用: 转换器模数转换器
文件页数/大小: 20 页 / 176 K
品牌: AD [ ANALOG DEVICES ]
 浏览型号AD7891AS-1的Datasheet PDF文件第2页浏览型号AD7891AS-1的Datasheet PDF文件第3页浏览型号AD7891AS-1的Datasheet PDF文件第4页浏览型号AD7891AS-1的Datasheet PDF文件第5页浏览型号AD7891AS-1的Datasheet PDF文件第6页浏览型号AD7891AS-1的Datasheet PDF文件第7页浏览型号AD7891AS-1的Datasheet PDF文件第8页浏览型号AD7891AS-1的Datasheet PDF文件第9页  
a
FEATURES
Fast 12-Bit ADC with 1.6 s Conversion Time
Eight Single-Ended Analog Input Channels
Overvoltage Protection on Each Channel
Selection of Input Ranges:
5 V, 10 V for AD7891-1
0 to +2.5 V, 0 to +5 V, 2.5 V for AD7891-2
Parallel and Serial Interface
On-Chip Track/Hold Amplifier
On-Chip Reference
Single Supply, Low Power Operation (85 mW max)
Power-Down Mode (75 W typ)
APPLICATIONS
Data Acquisition Systems
Motor Control
Mobile Communication Base Stations
Instrumentation
LC
2
MOS 8-Channel, 12-Bit
High Speed Data Acquisition System
AD7891
FUNCTIONAL BLOCK DIAGRAM
V
DD
V
DD
V
IN1A
V
IN1B
V
IN2A
V
IN2B
V
IN3A
V
IN3B
V
IN4A
V
IN4B
V
IN5A
V
IN5B
V
IN6A
V
IN6B
V
IN7A
V
IN7B
V
IN8A
V
IN8B
REF OUT/
REF IN
REF GND
+2.5V
REFERENCE
STANDBY
AD7891
M
U
X
TRACK/HOLD
ADDRESS
DECODE
12-BIT
ADC
DATA/
CONTROL
LINES
CLOCK
CONTROL LOGIC
WR CS RD EOC CONVST
MODE
AGND AGND DGND
GENERAL DESCRIPTION
PRODUCT HIGHLIGHTS
The AD7891 is an eight-channel 12-bit data acquisition system
with a choice of either parallel or serial interface structure. The
part contains an input multiplexer, an on-chip track/hold ampli-
fier, a high speed 12-bit ADC, a +2.5 V reference and a high
speed interface. The part operates from a single +5 V supply
and accepts a variety of analog input ranges across two models,
the AD7891-1 (± 5 V and
±
10 V) and the AD7891-2 (0 V to
+2.5 V, 0 V to +5 V and
±
2.5 V).
The AD7891 provides the option of either a parallel interface or
serial interface structure determined by the MODE pin. The
part has standard control inputs and fast data access times for
both the serial and parallel interfaces which ensures easy inter-
facing to modern microprocessors, microcontrollers and digital
signal processors.
In addition to the traditional dc accuracy specifications such as
linearity, full-scale and offset errors, the part is also specified for
dynamic performance parameters including harmonic distortion
and signal-to-noise ratio.
Power dissipation in normal mode is 90 mW typical while in
the standby mode this is reduced to 75
µW
typ. The part is
available in a 44-terminal plastic quad flatpack (PQFP) and a
44-lead plastic leaded chip carrier (PLCC).
1. The AD7891 is a complete monolithic 12-bit data acquisition
system combining an eight-channel multiplexer, 12-bit ADC,
+2.5 V reference and track/hold amplifier on a single chip.
2. The AD7891-2 features a conversion time of 1.6
µs
and an
acquisition time of 0.4
µs.
This allows a sample rate of
500 kSPS when sampling one channel and 62.5 kSPS when
channel hopping. These sample rates can be achieved using
either a software or hardware convert start. The AD7891-1
has an acquisition time of 0.6
µs
when using a hardware
convert start and an acquisition time of 0.7
µs
when using a
software convert start. These acquisition times allow sample
rates of 454.5 kSPS and 435 kSPS respectively for hardware
and software convert start.
3. Each channel on the AD7891 has overvoltage protection.
This means that an overvoltage on an unselected channel
does not affect the conversion on a selected channel. The
AD7891-1 can withstand overvoltages of
±
17 V.
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.
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., 1998