RL1024P Perkin Elmer Optoelectronics, RL1024P Datasheet - Page 28

• Manufacturer Part Number: RL1024P
• Manufacturer: Perkin Elmer Optoelectronics

26
analog optical isolators
www.optoelectronics.perkinelmer.com
Features
• High input-to-output voltage
• True resistance element output
• Single- or dual-element outputs
• Low cost
• Suitable for AC or DC use
• Wide range of input-to-output
• Low drive current
• Low “on” resistance, high “off ”
• Complete solid-state construction
Typical Applications
• DC Isolators
• Feedback Elements in Automatic
• Audio Limiting and Compression
• Noiseless Switching
• Logic Interfacing
• Remote Gain Control for
• Photochoppers
• Noiseless Potentiometers
Principle of Operation
Analog Optical Isolators are used in
many different types of circuits and
applications.
Available Related Products
Datasheets available upon request
isolation
available
characteristics
resistance
Gain Control Circuits
Amplifiers
VTL5C Series
LT3011 Series
LT9900 Series
Absolute Maximum Ratings @ 25°
Maximum Temperatures
Storage and Operating:
Cell Power:
Derate Above 30°C:
LED Current:
Derate Above 30°C:
LED Reverse Breakdown Voltage:
LED Forward Voltage Drop @ 20 mA:
Minimum Isolation Voltage @
70% Rel. Humidity:
Output Cell Capacitance:
Input/Output Coupling Capacitance:
Description
PerkinElmer Optoelectronics has been a leading manufacturer of
analog optical isolators (AOI) for over twenty years and makes a
broad range of standard parts under its trademark VACTROL
There are many kinds of optical isolators, but the most common
is the LED/phototransistor type. Other familiar types use output
elements such as light-sensitive SCRs, Triacs, FETs and ICs. The
major application for these silicon-based devices is to provide
electrical isolation of digital lines connected between different
pieces of equipment. The principle of operation is very simple.
When an input current is applied to the LED, the output photo-
transistor turns on. The only connection between the LED and
phototransistor is through light—not electricity—thus the term
optical isolator. These optical isolators are primarily digital in
nature with fast response times for interfacing with logic gates.
Rise and fall times of a few microseconds, faster for some
isolators, are typical.
The AOI also uses an optical link between input and output.
The input element is an LED and the output element is always
a photoconductive cell or, simply a photocell. Together, the
coupled pair act as an electrically variable potentiometer. Since
the output element of the AOI is a resistor, the voltage applied
to this output resistor may be DC and/or AC and the magnitude
may be as low as zero or as high as the maximum voltage rating.
Because the input will control the magnitude of a complex
waveform in a proportional manner, this type of isolator is an
analog-control element. AOIs may be used in the ON-OFF mode
but the fastest response time is only in the millisecond range.
A level-sensitive Schmitt trigger is required between the AOI
and logic gates when used in digital circuits.
Table of Contents
–40°C to 75°C
175 mW
3.9 mW/°C
40 mA
0.9 mA/°C
3.0 V
2.0 V (1.65 V Typ.)
VTL5C8 = 2.8 V (2.2 V typ.)
VTL5C9 = 2.8 V (2.2 V typ.)
VTL5C10 = 2.8 V (2.2 V typ.)
2500 VRMS
5.0 pF
0.5 pF
®
.