ANALOG DEVICES 5B45 Service Manual

Isolated, Frequency Input

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FEATURES

Isolated Frequency Input.
Amplifies, Protects, Filters, and Isolates Analog Input.
Generates an output of 0 to +5V proportional to input

frequency.
Model 5B45 accepts full-scale inputs from 500 Hz to 20 kHz.
Model 5B46 accepts full-scale input from20 Khz to 275 kHz.
Module circuitry can withstand 240v rms at the input screw-

terminals.
All 5B45 & 5B46 series modules are mix-and-match and Hot

Swappable.

APPLICATIONS

Industrial signal conditioning
Industrial signal isolation
Industrial signal filtering

PRODUCT OVERVIEW

The 5B Series represents an innovative generation of low cost,
high performance plug-in signal conditioners. Designed for
industrial applications, these modules incorporate highly
reliable transformer-based isolation and automated surface­mount manufacturing technology. They are compact,
economical components whose performance exceeds that
available from more expensive devices. Combining 1500 V rms
continuous isolation, +0.05% calibrated accuracy, small size and
low cost, the 5B Series is an attractive alternative to expensive
signal conditioners and in-house designs

All modules are potted and identical in pin-out and size (2.27” x

2.32” x 0.595”). They can be mixed and matched, permitting
users to address their exact needs, and may be “hot swapped
without disturbing field wiring or power. The isolated input
modules provide 0 to +5V or +5V outputs and accept J, K, T, E,
R, S, N, or B type thermocouples.

5B45 / 5B46

FUNCTIONAL BLOCK DIAGRAM

Figure 1. 5B45 & 5B46 Functional Block Diagram

There are also a number of backplanes and mounting sockets
which provide a complete signal conditioning solution for end
users. Each backplane incorporates screw terminals for field
wiring inputs and outputs and cold junction sensors for
thermocouple applications.

These signal conditioners are designed to provide an easy and
convenient solution to signal conditioning problems of both
designers and end users in measurement and control
applications. Typical uses include microcomputer-based
measurement systems, standard data acquisition systems,
programmable controllers, analog recorders and dedicated
control systems. The 5 B series modules are ideally suited to
applications where monitoring and control of temperature,
pressure, f low, rotation and other analog signals are required.

The 5B Series modules and backplanes are approved by Factory
Mutual (FM) and the 5B Series modules are approved by the
Canadian Standards Association (CSA) for use in Class 1,
Division 2, Groups A, B, C, and D locations. These approvals
certify that the 5B Series is suitable for use in locations where a
hazardous concentration of flammable gas may exist only under
fault conditions of operation. Equipment of this category is
called “nonincendive” and they need no special enclosures or
other physical safeguards.

These modules feature complete signal conditioning functions
including 240 V rms input protection, filtering, chopper
stabilized low drift +1 uV/oC amplification, 1500 V rms
isolation, and sensor excitation when required.

All modules feature excellent common mode rejection and
meet industrial transient surge withstand specifications.

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.

The 5B series modules and backplanes have been tested and
passed the stringent heavy industrial requirements of the
European Union’s electromagnetic compatibility (ENC)
directive – EN50082-1 and EN50081-2. When used according
to installation directions (refer to 5B series User Manual), any
errors caused by EMI/RFI interference will be less than 0.1% of
the full scale 5B measurement range for field strengths up to 10
V/M and frequencies up to 1 GHz.

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

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GENERAL DESCRIPTION

The 5B45 and 5B46 are single-channel isolated frequency input
modules that produce a 0 to +5V output proportional to input
frequency. Model 5B45 accepts full-scale inputs ranging from
500 Hz to 20 kHz. Model 5B46 accepts full-scale inputs ranging
from 20 kHz to 275 kHz. Both models allow the user to set the
threshold to either 0 V (for zero crossing signals) or +1.4 V (for
positive level signals), and the hysteresis to either +25 mV or
+400 mV (all input types).

The 5B45 and 5B46 protect the computer side from field-side
over-voltage faults. All models withstand 240 V rms at their
input terminals without damage, thereby shielding computer­side circuitry from field-side over-voltage conditions. In
addition, all 5B45 and 5B46 models are mix-and match and hot­swappable, so can be inserted or removed from any socket in
the same backplane without disrupting system power.

Inside 5B45 & 5B46 Modules – The 5B45/46 internal circuitry
compares the input signal to the user-selected threshold (V
and hysteresis (V
exceed the combined threshold and hystersis levels (V
+

VH)will trigger a comparator at a rate determined by the input
frequency. The comparator output is then transmitted across a
proprietary transformer-coupled isolation barrier and
converted to a high-level analog signal. This signal is then
filtered by a multi-pole low pass Butterworth filter and buffered

). Signals of virtually any wave shape that

H

)

T

T

5B45 / 5B46

to provide a low-noise, low-impedance output signal that is
accurately proportional to input frequency.

Simple Setup and Versatile Choices – Setting the threshold
and hysteresis values is a simple matter of externally wiring to
the backplane screw terminals. The threshold for measuring a
zero-crossing voltage waveform (such as sine waves) is set to 0
volts by connecting the input signal across screw-terminals 4
and 3. The threshold for a positive level signal (such as a TTL or
pulse train waveform) is set at +1.4V by connecting the input
signal across terminals 3 and 2. Hysteresis for both input signal
types is set at +
adding a jumper between screw terminals 1 and 4. Response
time is a function of a modules rated input frequency range.
(See the 5B45 and 5B46 Model Table).

The input circuit is fully floating and isolated from the output
and power commons. In addition, the output section acts as a
third floating port towards eliminating possible problems from
ground loops and power supply noise. The output common
must be held within +

A series output switch eliminates the need for external
multiplexing in many applications. The switch is turned on by
an active-low enable input. If the switch is to be on at all times,
the enable-input should be grounded to power common as it is
on the 5B01 and 5B08 backplanes..

400 mV but can be changed to +25 mV by

3V of power common.

.

Figure 2

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5B45 and 5B46 Models Available

Model Input Range Output Range Rise/Fall Time Step Response

5B45-01

5B45-02

5B45-03

5B45-04

5B45-05

5B45-Custom

Model

0 Hz to 500 Hz 0 V to +5 V 80 ms 150 ms

0 Hz to 1 kHz 0 V to +5 V 60 ms 140 ms

0 Hz to 2.5 kHz 0 V to +5 V 50 ms 130 ms

0 Hz to 5 kHz 0 V to +5 V 50 ms 130 ms

0 Hz to 10 kHz 0 V to +5 V 50 ms 130 ms

* *

Input Range Output Range Rise/Fall Time Step Response

5B45 / 5B46

5B46-01

5B46-02

5B46-03

5B46-04

5B46-Custom

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

0 Hz to 25 kHz 0 V to +5 V 15 ms 44 ms

0 Hz to 50 kHz 0 V to +5 V 7 ms 22 ms

0 Hz to 100 kHz 0 V to +5 V 4 ms 12 ms

0 Hz to 250 kHz 0 V to +5 V 4 ms 9 ms

* *

5B45 and 5B46 Specifications

Description Model 5B45 Model 5B46

Frequency Input

Standard Ranges Refer to Model Table Refer to Model Table

Custom Ranges 500 Hz span, min.; 20 kHz span, max. 20 kHz span, min.; 275 kHz span, max.

Over-range 20% of Span *

Voltage Range 70 mV rms min. 240 V rms max. *

Waveforms Sine, Square, Triangle, Pulse Train *

Pulse Width (Pulse Train Inputs) 2 µs min. *

Threshold Options Zero Crossing or TTL (+1.4 V) *

TTL Input, Low (-40°C to +85°C) 0.8 V max. *

TTL Input, High (-40°C to +85°C) 2.0 V min. *

1

Hysteresis Options

Output Ranges (R

Initial @ +25°C ±0.05% Span (±0.1% Span, max.) *

Nonlinearity ±0.005% Span (±0.015% Span, max.) *

Output Offset vs. Temperature ±20 µV/°C *

Gain vs. Temperature ±20 ppm/°C *

Input Bias Current, V

Small Signal, V

Large Signal, Vin > 5 V peak-peak

±25 mV or ±400 mV *

> 50 k Ω)

L

< 5 V peak-peak

in

< 5 V peak-peak

in

-5 V to +5 V or 0 V to +5 V *

2

Accuracy

100 µA *

Input Impedance

5 M Ω

40 k Ω || 330 pF

*

*

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