Analog Devices B40 41 Datasheet

Isolated Wideband Voltage Input

FEATURES

Interfaces, amplifies, protects& filters wide-bandwidth (h0
kHz) single-channel analog voltage inputs.

Module provides simultaneous precision voltage and
current outputs.

Module circuitry can withstand 130v rms at the current
output screw-terminals.

All 3B40 & 3B41 series modules are mix-and-match and Hot
Swappable.

APPLICATIONS

Industrial signal conditioning
Industrial signal isolation
Industrial signal filtering

PRODUCT OVERVIEW

The 3B Series of Signal Conditioning I/o Subsystems provide a
low-cost, versatile method of transferring analog transducer
signals to a data acquisition, monitoring or control system
without the inherent noise, non-linearity, drift and extraneous
voltages. The modules are designed to directly accept analog
signals from Thermocouples, RTD’s, AC and DC Strain Gages,
Torque Transducers, Frequency Transducers, LVDTs, millivolt
or process current signals. The modules amplify, isolate,
linearize and convert the transducer output signals to
standardized analog inputs for high-level analog I/O
subsystems. The 3B Series Subsystem consists of a 10” relay
rack with universal mounting backplane and a family of plug-in
(up to 16 per rack) input and output signal conditioning
modules.

Eight and four channel backplanes are also available. Each
backplane incorporates screw terminals for sensor inputs and
current outputs and a 26-pin connector for high-level single­ended voltage outputs to the user’s equipment.

The input modules feature complete signal conditioning
circuitry optimized for specific sensors or analog signals and
provide two simultaneous high-level analog outputs: 0 to +10V

10V) and 4-20 mA (or 0-20 mA).

(or +

3B40 / 3B41

FUNCTIONAL BLOCK DIAGRAM

Figure 1. 3B40 & 3B41 Functional Block Diagram

Output modules accept 0 to +10V (or +10V) single-ended
signals and provide an isolated 4-20 mA (or 0-20 mA) process
signal. All modules feature a universal pin-out and may be
readily hot-swapped under full power and interchanged without
disrupting field wiring.

The Analog Devices 3B Series Signal Conditioning Subsystem is
designed to easily handle signal conditioning problems in
measurement and control applications. Some typical uses are in
microcomputer-based data acquisition systems, programmable
controllers, analog recorders, dedicated control systems, and any
other applications where monitoring of temperature, pressure,
flow and analog signals are required. Since each input module
features two simultaneous outputs, the voltage output can be
used to provide an input to a microprocessor-based data
acquisition or control system while the current output can be
used for analog transmission, operator interface, or an analog
backup system.

Each input module is a single-channel signal conditioner which
plugs into a socket on the backplane and accepts its signal from
the input screw terminals. All input modules provide input
protection, amplification and filtering of the input signal,
accuracy of +
modules), and feature two high-level analog outputs that are
compatible with most process instrumentation. The isolated
input modules also provide +

The choice of a specific 3B module depends upon the type of
input signal. Input modules are available to accept millivolt, volt,
process current, thermocouple, RTD, AC and DC strain gage,
frequency and LVDT inputs. The voltage output of each module
is available from the system I/O connector while the current
output is available on the output screw terminals.

0.1%, low drift of +1 uV/ oC (low-level input

1500 V peak isolation.

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.
Tel: [phone]
Fax: [phone] © 2004 Analog Devices, Inc. All rights reserved.

www.analog.com

GENERAL DESCRIPTION

The 3B40 and 3B41 are wide-bandwidth (10kHz) single­channel signal conditioning modules which amplify, isolate,
filter and protect analog input voltages and provide
simultaneous precision voltage and current outputs. Each
module performs complete signal conditioning, including
isolating (+
protecting their computer side outputs from damage and loss of
signal integrity, and shielding their inputs from damage from
field-side over-voltage faults up to 220 V rms. The current
output withstands 130V rms without damage and interfaces
user equipment through screw terminals located on the 3B
Series backplane. Each plug-in, mix-and-match, hot-swappable
module is easily field calibrated via front-panel zero and span
adjustments for both voltage and current outputs.

3B Series Custom-Ranging Program – Externally­programmable versions, Models 3B40-00 and 3B41-00, enable
the user to configure a special input range by using the optional
plug-on AC1310 ranging card, which houses user-supplied
resistors to determine zero and span. To facilitate selecting
resistors, a Windows program, 3B-CUSTOM, calculates resistor
values based on the user-desired input/output ranges.

1500 V peak input-to-output and power) and

3B40 / 3B41

assures long-term stability. At the amplifier input, a stable, zero­scale input voltage is subtracted from the input signal to set the
zero-scale value. Zero suppression can exceed 100% of the input
range. This is ideal for expanded-scale applications requiring
high-resolution measurement of a selected portion of an input
signal. For user convenience, the zero and span can be factory
configured to meet custom range needs (Models 3B40­CUSTOM and 3B41-CUSTOM) or can be externally
programmed (Models 3B40-00 and 3B41-00) via user supplied
resistors inserted in the optional AC1310 plug-on ranging card.
Internal low-pass filtering with a 10 kHz cutoff (-3dB) is
determined by a two-pole Butterworth filter.

Signal isolation is accomplished by transformer coupling with a
proprietary modulation technique for linear, stable and reliable
performance. The differential input circuit on the field side is
fully floating, eliminating the need for any input grounding. A
demodulator on the computer side of the signal transformer
recovers the original signal, which is then filtered and buffered
to provide a low-noise, low-impedance output voltage: this
output also drives a voltage-to-current (V/I) converter to
provide a simultaneous current output for interfacing versatility.

A chopper-stabilized low-drift (+

.

1uV/oC) input amplifier

.

Figure 2

Rev. 0 | Page 2 of 8

3B40 and 3B41 Models Available

Model Input Range Output Ranges1

3B40-00

3B40-01
3B40-02
3B40-03

3B40-Custom

Model Input Range Output Ranges

3B41-00
3B41-01
3B41-02
3B41-03

3B41-Custom

1

Output current range may be user programmed to 4 mA to 20 mA using jumper supplied.

2

Requires AC1310 ranging card.

* Custom Input/Output ranges are available. Refer to configuration guide.

Externally Programmable

-10 mV to +10 mV -10 V to +10 V & 0 mA to 20 mA

-50 mV to +50 mV -10 V to +10 V & 0 mA to 20 mA

-100 mV to +100 mV -10 V to +10 V & 0 mA to 20 mA
* *

Externally Programmable

-1 V to +1 V -10 V t o +10 V & 0 mA to 20 mA

-5 V to +5 V -10 V t o +10 V & 0 mA to 20 mA

-10 V to +10 V -10 V to +10 V & 0 mA to 20 mA
* *

3B40 / 3B41

2

-10 V to +10 V & 0 mA to 20 mA

1

2

-10 V to +10 V & 0 mA to 20 mA

3B40 and 3B41 Specifications
(typical @ +25°C and ±15 V dc, and +24 V dc Power)

Description Model 3B40 Model 3B41

Input Ranges

Standard Ranges ±10 mV to ±1 V ±1 mV to ±10 V
Custom Ranges ±5 mV to ±1 V ±0.5 V to ±20 V

Output Ranges

Voltage (R
Current (R
Maximum Current Output Span 0 mA to 31 mA *

Initial @ +25°C ±0.1% Span *
Nonlinearity ±0.02% Span *

Voltage Output

Input Zero ±2 µV/°C (RTI) ±10 µV/°C (RTI)
Output Zero ±25 µV/°C (RTI) *
Span ±25 ppm of Reading/°C *

Zero and Span Adjustment Range
Input Bias Current
Input Resistance

Input, 10 MHz Bandwidth 5 µV rms *

> 2 kΩ)

L

= 0 to 850 Ω)1

L

4

-10 V to +10 V *
4 mA to 20 mA or 0 mA to 20 mA *

Noise

2

Accuracy

Stability vs. Temperature

±5% of Span *
=5 nA *
200 M Ω 250 kΩ

Rev. 0 | Page 3 of 8