AD 7B22

Isolated High Level Voltage Output
7B22
FEATURES
FUNCTIONAL BLOCK DIAGRAM
Unity gain single-channel signal conditioning output
module.
Interfaces and filters a +10 V input signal and provides an
isolated precision output of +10V.
All 7B22 series modules are mix-and-match and Hot
Swappable.
APPLICATIONS
Industrial signal conditioning
Industrial signal isolation
Industrial signal filtering
PRODUCT OVERVIEW
The 7B Series of signal conditioners feature small size, low cost
and a wide output voltage range for a variety of applications
including process control and factory-floor environments. The
single-channel 7B modules accept inputs from a range of
transducers and are fully rated over the extended -40oC to
+85oC industrial temperature range.
All 7B Series modules are rated for a nominal power supply
input of +24 VDC; and, for maximum flexibility, they will
accept supply voltages in the +14 VDC to +35 VDC range. The
input modules, with the exception of the 7B21, provide a highlevel output voltage that is factory configured for either the +1
V to +5 V or 0 V to +10 V range. The 7B21 is a unity gain,
isolated input module with an input/output range of +10V.
Output modules are available that provide either isolated
process current or isolated bipolar voltage output. Model 7B39
converts either a +1 V to +5 V input to a 4 to 20 mA output or a
0 V to +10 V input to a 0-20 mA output. The input/output
ranges of the 7B39 are factory configured. The 7B22 is a unity
gain module that provides an isolated +10V output signal. All
modules have a universal pin-out and may be readily hotswapped under full power without disrupting field wiring.
Each module accepts analog transducer signals and transfers
them to a process control or factory data collection system
without the inherent noise, non-linearity, drift and extraneous
voltages which frequently accompany the signals.
Figure 1. 7B22 Functional Block Diagram
The modules feature a maximum nonlinearity of +0.02% and
are factory calibrated to guarantee a maximum accuracy
specification of +0.1%.
The 7B Series offers up to 1500 V rms continuous common
mode voltage isolation and 120 V rms of field wiring input
protection. The power supplies necessary to drive each of the
individual module’s input circuitry are internally isolated,
enabling the 7B Series modules to offer true channel-to-channel
isolation of the input signals.
The modules directly accept analog signals from
thermocouples, RTDs, current loop powered transmitters, and
other process control signals. The 7B Series modules amplify,
linearize, isolate, protect and convert the transducer output
signals to standardized analog inputs for high-level analog I/O
subsystems. The 7B Series Subsystem consists of 19-inch rackcompatible hardware (model AC 1363), with universal
mounting backplane and a family of plug-in (up to 16 per
backplane) input and output signal conditioning modules. Four, eight-, and sixteen-channel backplanes are available. Each
backplane incorporates screw terminals for easy power
connections and field wiring, and includes a 25-pin D-type
connector for interfacing the high-level single-ended voltage
outputs to the user’s equipment. Gold-plated sockets are
provided on each channel of the backplane to ensure the
reliability of each module’s electrical connection.
Rev. 0
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.
Specifications subject to change without notice. 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.
www.analog.com
Tel: 781.329.4700
Fax: 781.326.8703
© 2004 Analog Devices, Inc. All rights reserved.
7B22
GENERAL DESCRIPTION
voltage powers the input side of the 7B22. The oscillator on the
input side provides the square wave carrier signal used by the
modulator and also drives the power transformer. The signal at
the secondary of the transformer is used in the demodulator
and is also converted to a DC voltage that powers the circuit on
the module’s output. The two-pole output filter and subsequent
buffer ensures that a low noise, low impedance (<1Ω) signal is
available at the isolated output to drive loads down to 5 kΩ.
The 7B22 is a unity gain single-channel signal conditioning
output module that interfaces and filters a +10 V input signal
and provides an isolated precision output of +10 V. The output
voltage appears at the 7B Series backplane screw terminal block.
Model 7B22 features a nonlinearity of +0.02% maximum and an
accuracy of +0.1% maximum (+0.01% typical). Providing 1500
V rms of galvanic transformer based isolation, output-to-input
and power, the 7B22 offers a common mode rejection (CMR) of
100 dB @ 50/60 Hz to preserve the integrity of low level signals
in noisy environments. The 7B22 is mix-and-match and hotswappable with other 7B Series modules, so it can be inserted or
removed from any socket in the same backplane without
disturbing system power. Model 7B22 is rated to operate with a
nominal +24 VDC supply.
The input and floating isolated voltage output of Model 7B22
are protected up to +35 VDC. The input signal from the user’s
system is buffered and then used to modulate the amplitude of a
square wave carrier. The modulated signal is transmitted across
the signal transformer and demodulated to retrieve the original
input voltage signal. This voltage is then filtered by a two-pole
low pass 400 Hz filter. The nominal +24 VDC module supply
Figure 2
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7B22
7B22 Models Available
Model
Input Range
7B22
Output Range
-10 V to +10 V
-10 V to +10 V
7B22 Specifications
(typical @ +23°C ±5°C and Vs = +24 V dc)
Description
Model 7B22
Output Range (RL > 5 kΩ)
Standard Ranges
-10 V to +10 V (-14 V to +14 V, maximum)
Custom Ranges
Not Available*
Input Range
-10 V to +10 V
Accuracy1
Initial @ +25°C
±0.01% Span (±0.1% Span, maximum)
Nonlinearity2
±0.02% Span, maximum
Span vs. Temperature
±35 ppm/°C
Output Offset vs. Temperature
±0.001% Span/°C
Input Bias Current
+3 nA
Input Resistance
Power ON
2 MΩ
Power OFF
30 kΩ, minimum
Output Noise
5 MHz Bandwidth
7 mV peak
10 Hz to 100 kHz Bandwidth
3 mV rms
0.1 Hz to 10 Hz Bandwidth
6 µV peak
Bandwidth, -3 dB
400 Hz
Output Rise Time, 10% to 90% Span
1 ms
Normal Mode Rejection @ 50/60 Hz
60 dB
Common-Mode Voltage (CMV)
Output-to-Input and Power
1500 V rms continuous
Common Mode Rejection (CMR)
Output-to-Input and Power @ 50/60 Hz
100 dB
Input Protection
±35 V dc, continuous
Input Transient Protection
ANSI/IEEE C376.90.1-1989
IEEE-STD 472
IEC 255-4, Class II
Output Resistance
<1Ω
Power Supply
Voltage Range, Operating
+19 V dc to +29 V dc
Current
+20 mA, maximum
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7B22
Sensitivity
±0.0001%/% of Vs
Mechanical Dimensions
1.663" x 2.11" x 0.563"
(42.24 mm x 53.6 mm x 14.3 mm)
Weight
60 grams
Environmental
Temperature Range
Operating
-40°C to +85°C
Storage
-40°C to +85°C
Relative Humidity, 24 hours
0 to 90% @ +60°C non-condensing
ESD Sensitivity
IEC 801-2, Level 2
RFI Susceptibility
±0.5% Span error @ 400 MHz, 5 Watt, 3 ft
Warm-up time required to meet specifications is approximately 10 minutes.
* Contact factory for OEM requirements.
1
Includes the combined effects of repeatability, hysteresis, and nonlinearity.
2
Nonlinearity is calculated using best-fit straight line method.
Specifications subject to change without notice.
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7B22
PIN CONFIGURATIONS AND FUNCTIONAL DESCRIPTIONS
Figure 3 7B22 Input Field Connections
Table 1. Pin Function Descriptions—
Pin
No.
0
1
2
3
4
5
Input Module Function
Output Module Function
SENSOR INPUT
INPUT HIGH
INPUT LOW
POWER SUPPLY (DC)
OUTPUT VOLTAGE
OUTPUT & POWER
COMMON
NOT USED
OUTPUT HIGH
OUTPUT LOW
POWER SUPPLY (DC)
INPUT VOLTAGE
INPUT AND POWER
COMMON
Figure 4 . Model 7B Series Module, with pin-out assignments.
ESD CAUTION
ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on the human
body and test equipment and can discharge without detection. Although this product features proprietary ESD
protection circuitry, permanent damage may occur on devices subjected to high energy electrostatic discharges.
Therefore, proper ESD precautions are recommended to avoid performance degradation or loss of functionality.
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7B22
OUTLINE DIMENSIONS
Figure 5. Outline Dimensions
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7B22
NOTES
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7B22
NOTES
© 2004 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective companies.
D05170-0-10/04(0)
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