DAS-4
DATA ACQUISITION LEGACY PRODUCTS
Low-Cost, 8-Channel, 8-Bit
Analog Input Board
FEATURES
• 8 A/D channels with 8-bit
resolution
• 7 digital I/O bits (4 outputs, 3
inputs)
• ±5 volt inputs (for 39mV
resolution)
• Interrupt handling capability
APPLICATIONS
• Data logging
• Alarm condition monitoring
• Laboratory automation
• Student experiments
• Home experiments
• Energy management
Functional Description
The DAS-4 is an extremely low cost, yet powerful analog input board for the IBM PC/XT/AT and
compatibles. The DAS-4 includes 8 single-ended analog input channels with an 8-bit successive
approximation A/D converter. The 8-bit resolution combined with the DAS-4’s fixed ±5V full-scale
input range provide a minimum resolution of 0.039V (39mV).
Seven bits of TTL/CMOS-compatible digital I/O are provided on the board, 4 digital outputs and 3
digital inputs. Each output will handle 5 standard TTL loads and can sink 8mA. An external interrupt input is provided that is jumper-selectable to any of the PC interrupt levels (2–7). This allows
the DAS-4 to sample data triggered by an external digital signal. +5V and ±12V from the PC are
provided on the DAS-4’s connector, allowing external circuitry to be operated from the computer.
Software
The Mode Call Driver included with the DAS-4 simplifies programming and supports BASICA,
QuickBASIC, and other interpreted BASIC languages. This software package also includes
example programs, initialization and setup routines, and a simple strip-chart recorder emulation routine.
SPECIFICATIONS
Analog Inputs
A/D TYPE: Successive approximation
CONVERSION TIME: 20µs typ, 30µs max
MONOTONICITY: Guaranteed over operating temperature range
LINEARITY: ±1 bit
ACCURACY: 0.2% of reading ±1 bit
OVERVOLTAGE: Continuous single channel to ±35V
CONFIGURATION: Single ended
INPUT CURRENT: 100nA max at 25°C
TEMPERATURE COEFFICIENTS: Gain drift ±50ppm/°C of FS max
Zero drift ±10µV/°C max
SAMPLE & HOLD ACQ TIME: 10µs to 0.1% typ time for full-scale step
input
VOLTAGE REFERENCE OUTPUT
REF. VOLTAGE: +5.0V ± 0.2V
TEMP. COEFFICIENT: 50ppm/°C max
LOAD CURRENT: ±2mA max
DIGITAL I/O
INPUTS (& INTERRUPTS) (LSTTL): 3
INPUT LOW: V
INPUT HIGH: V
OUTPUTS (STANDARD LSTTL): 4
OUTPUT LOW: V
OUTPUT HIGH: V
ENVIRONMENTAL
TEMPERATURE: 0 to 50°C (operating); –20 to +70°C (storage)
HUMIDITY: 0 to 90% non-condensing
WEIGHT: 4oz (120g)
DIMENSIONS: 4.25in × 5.0in (10.8cm × 12.7cm)
= 0.8V max; IIL= –0.4mA max
IL
= 2.0V min; IIH= 20µA max
IH
= 0.5V max @ IOL= 8mA
OL
= 2.4V min @ IOH= –400µA
OH
POWER REQUIREMENTS
+5V: 105mA typ/175mA max
+12V: 26mA typ/30mA max
–12V: 16mA typ/20mA max
Connector Pin Assignments
19
DIGITAL
OUTPUTS
VREF
L.L. GND
L.L. GND
L.L. GND
L.L. GND
L.L. GND
L.L. GND
L.L. GND
DIG COM
+12V
OP4
OP3
OP2
OP1
37
18
36
17
35
16
34
15
33
14
32
13
31
12
30
11
29
10
28
9
27
8
26
7
25
6
24
5
23
4
22
3
21
2
20
1
REAR VIEW
IN0
IN1
IN2
IN3
IN4
IN5
IN6
IN7
+5V
DIG GND
IP3
IP2
IP1
INT IN
-12V
ANALOG
INPUT
CHANNELS
DIGITAL
INPUTS
ORDER DESCRIPTION
DAS-4 8-Channel, 8-Bit Analog Input
Board
OPTIONS
STA-U Screw Terminal Accessory Board
STP-37 Screw Terminal Panel
C-1800 DAS-4 to STA-U or STP-37 Cable
STC-37 Screw Terminal Connector
See page 479 for descriptions of all accessories.
QUESTIONS?
1-800-552-1115 (U.S. only)
Call toll free for technical assistance,
product support or ordering information, or
visit our website at www.keithley.com.
www.keithley.com
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