AL8400 DATA ACQUISITION PRODUCT LINE MODEL 2111 ADC802
1. FEATURES
¾ Hi-Z Differential Inputs
•
± 41 Volt Range
•
± 40 Volt Common-Mode Offset Voltage
¾ 8 Multiplexed Inputs
¾ 16-Bit ADC
¾ Over Voltage Protection
•
±300 V
¾ Fully Independent Channel Placement in PCM Stream
¾ Fully Digital Calibration of Each Channel
2. PURPOSE
This module provides 16-bit digitization of eight analog input channels. Each differential input presents one
Meg-Ohm input impedance, is overvoltage protected and accepts a large common mode offset voltage.
3. FUNCTIONAL DESCRIPTION
The ADC802 module is designed to be installed in an Apogee Labs AL8400 Data Acquisition System.
Within this environment the PGMGEN module provides all control functions. Format definition commands are received by the PCMGEN from either the front panel or remote control port on the AL8400. These commands are interpreted and converted to register-level instructions, which are passed through the backplane setup bus to this card. No operational information is stored on this module.
Characteristic of the AL8400, each input channel is independently mapped to a location or locations in the output serial PCM frame. This feature is totally electronic facilitating rapid system configuration without the need to deal with patch-cords to define signal paths.
Calibration of each channel is a digital process. There are no potentiometers or other components that require adjustment. Calibration values for each ADC802 module in the system are stored in non-volatile memory only on the PCMGEN module and are restored to each ADC upon the application of power to the system.
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10.20.06
210 South 3 rd
Street, North Wales, PA 19454
Tel: 215.699.2060 Fax: 215.699.2061
E-mail: sales@apogeelabs.com

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INPUT SIGNAL
CONNECTOR DB-25
1
4
2
1k
1
9k 990k
2
3 4
1 Meg Ohm
1
ANALOG
GND
22pf
330pf
22pf
29.4k
Ohm
29.4k
Ohm
+
Instrumentation
Amplifier
-
1 OF 8 INPUT CIRCUITS
8:1 MUX
6
7
8
1
2
3
4
O
5
ADC 16- Bits
V-Ref.
2.5V
SELECT
CONVERT
DATA
16- Bits
16- Bits
Control
HOLD
REGISTERS
&
OUTPUT
CONTROL
DAV
EOW
EOF
Figure 1: Model 2111 ADC802 Functional Block Diagram
4. SPECIFICATIONS
GENERAL
2 Independent channels
Single Slot Module (3” x 6” x 0.9”)
Semi-Automatic Channel Calibration
INPUT
DB-25 M connector
8 Differential analog inputs
±41 Volt Differential range
±40 Volt Common-Mode range
±300V Overvoltage protection
Analog ground returns provided
Chassis ground on connector shell
OUTPUT
16-bit ADC
0.05% FS accuracy
Offset binary code
Sample Rate = PCM Frame Rate
1 sample/sec to 1k samples/sec
OPERATING TEMPERATURES
Operating Temperature Range of 0°C to 50°C
OPERATING HUMIDITY
80% relative humidity (rh) maximum,
15% rh, minimum
Apogee Labs Inc. products are sold by description only. Apogee Labs Inc. reserves the right to make changes in circuit design, software, hardware and/or specifications at any time without notice. Although Apogee Labs Inc. believes that the information provided is current and accurate, Apogee Labs Inc. does not assume any responsibility or liability for the use of any product described. It is the responsibility of the user to determine appropriate use of the product in any given application .
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