Part Number: IS181D

Manufacturer: Isocom Components 2004 Ltd.


Shipped from: Shenzhen/HK Warehouse

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Technical Specifications of IS181D

Datasheet  IS181D datasheet
Category Isolators
Family Optoisolators – Transistor, Photovoltaic Output
Manufacturer Isocom Components 2004 LTD
Packaging Tape & Reel (TR)
Part Status Active
Number of Channels 1
Voltage – Isolation 3750Vrms
Current Transfer Ratio (Min) 300% @ 5mA
Current Transfer Ratio (Max) 600% @ 5mA
Turn On / Turn Off Time (Typ)
Rise / Fall Time (Typ) 4μs, 3μs
Input Type DC
Output Type Transistor
Voltage – Output (Max) 80V
Current – Output / Channel 50mA
Voltage – Forward (Vf) (Typ) 1.2V
Current – DC Forward (If) (Max) 50mA
Vce Saturation (Max) 200mV
Operating Temperature -55°C ~ 100°C
Mounting Type Surface Mount
Package / Case 4-SMD, Gull Wing
Supplier Device Package


Welcome to the complete guide on the IS181D optoisolator transistor output! In this article, we will delve into the fascinating world of optoisolators, specifically focusing on the IS181D model. Whether you’re a seasoned hobbyist or just starting out, this comprehensive guide will provide you with all the information you need to understand, utilize, and maximize the potential of this remarkable electronic component. So, let’s embark on this exciting journey together!

What is an Optoisolator?

Electronic devices called optoisolators, also referred to as optocouplers, use light to provide electrical isolation between two circuits. They don’t have a direct electrical connection between them because they are made up of an input LED and an output phototransistor, or photothyristor.

Optoisolators offer several advantages

  1. Enhanced Electrical Isolation: Protects sensitive components from voltage surges, EMI, and ground loops.
  2. Noise Reduction: Ensures cleaner and more reliable signal integrity by reducing the transmission of noise.
  3. Signal Level Shifting: Enables interfacing between circuits with different voltage levels.
  4. Protection and Safety: Provides an extra layer of protection in safety-critical systems.
  5. Galvanic isolation Eliminates direct electrical connections, preventing interference and damage.
  6. High-Speed Data Transfer: Enables secure and reliable communication in telecommunications

Electrical isolation is important because it:

  1. Ensures Safety: Protects personnel and equipment from dangerous voltages.
  2. Provides Noise Immunity: Mitigates the impact of electrical noise on circuits.
  3. Eliminates Ground Loops: Prevents circulating currents and potential damage.
  4. Enables Voltage Compatibility: Allows interfacing between circuits with different voltage levels.
  5. Maintains Data Integrity: Minimizes signal corruption and ensures reliable data transmission.

Optoisolators are widely used in power supply designs, motor control, digital communications, and industrial automation, among other applications.

The Importance of Isolation in Electronics

Solation is crucial in electronics for safety and performance. Optoisolators offer reliable electrical isolation through light-based communication. Key reasons for using optoisolators include:

  1. Safety: Optoisolators protect personnel and equipment by separating high-voltage or hazardous circuits from low-voltage control circuits.
  2. Noise Immunity: They prevent the transmission of electrical noise, ensuring cleaner and more reliable signal integrity.
  3. Ground Potential Differences: Optoisolators eliminate ground loops, reducing noise, distortions, and potential damage.
  4. Voltage Compatibility: They enable interfacing between circuits with different voltage levels.

Galvanic isolation, high noise immunity, and a variety of configurations for varied applications are all features of optoisolators. For effective electrical isolation and top performance in electronic systems, they are crucial.

Overview of the IS181D Optoisolator Transistor Output

An optoisolator with a transistor output specifically developed for electrical isolation in electronic circuits is the IS181D. Let’s examine its technical specs, features, pin configuration, and packaging information in more detail:

Technical Specifications and Features

Strong isolation between the input and output sides is ensured by the IS181D’s remarkable isolation voltage of 3750 Vrms (root mean square).

It makes use of a transistor output arrangement, which enables effective signal amplification and switching.

Current Transfer Ratio (CTR): The CTR is a critical quantity that denotes the proportion of output current to input current. A high CTR on the IS181D indicates effective signal transmission.

Response Time: It has a short response time that makes signal switching and transmission possible quickly.

Temperature Range: The IS181D functions within a predetermined temperature range, ensuring dependable performance in a variety of environmental settings.

Details about the IS181D optoisolator’s pin configuration and package: The manufacturer may change how the IS181D optoisolator is packaged. It is made up of numerous pins, each with a distinct purpose. A comprehensive overview of pin configuration is given below:

Input Side

  • Anode (A): This pin is connected to the anode (positive terminal) of the input LED.
  • Cathode (K): This pin is connected to the cathode (negative terminal) of the input LED.

Output Side

  • Collector (C): This pin is connected to the collector terminal of the output transistor.
  • Emitter (E): This pin is connected to the emitter terminal of the output transistor.
  • Base (B): This pin is connected to the base terminal of the output transistor.

As different manufacturers may have variations in pin assignments and packaging types, it is crucial to refer to the datasheet or product documentation specifically for the IS181D model to acquire precise and complete information on pin configuration and package.

Technical features, including the high isolation voltage, effective output transistor arrangement, and quick response time of the IS181D optoisolator transistor output, are noteworthy.

Common Applications of the IS181D Optoisolator Transistor Output

With its transistor output structure, the IS181D optoisolator has a wide range of applications in several sectors. Here are a few typical uses for which the IS181D shines:

Systems for Industrial Automation and Control

Systems for industrial automation and control work well with the IS181D. It offers dependable electrical separation between control circuits and industrial machinery that is loud or powerful. It improves the overall effectiveness and stability of automation systems and ensures the safety of control circuits.

Motor-Drive Circuits

Circuits for motor drives need exact control and protection measures. In motor drive circuits, the IS181D can be used to separate control signals from power circuits. It ensures effective and secure motor control operations by protecting delicate control circuitry from voltage spikes, electrical noise, and potential ground loop problems.

Power Supply Designs

Power supply designs frequently use delicate control circuitry and high-voltage components. To ensure safety against voltage variations, noise, and possible hazards, the IS181D can be used to create isolation between the power supply and the control section. While safeguarding the control components, it aids in maintaining reliable and clean power delivery.

Digital Signal Isolation

The IS181D offers secure and dependable communication between various digital circuits in digital signal isolation applications. It guarantees the transfer of digital signals across various voltage ranges and offers efficient noise immunity. This makes it helpful for applications like microcontroller interfacing, PLCs (Programmable Logic Controllers), and data transmission systems.

These are only a few examples of the numerous uses for which the output of the IS181D optoisolator transistor is suitable. It is an important component in a variety of electronic systems across sectors because of its capacity to provide electrical isolation, noise reduction, and voltage compatibility.


Congratulations on completing our comprehensive guide to the IS181D optoisolator transistor output! We hope it has provided valuable insights into the world of optoisolators and how the IS181D can enhance your electronic projects.

Incorporating the IS181D into your designs unlocks new possibilities, ensuring reliable and safe electrical isolation. Whether you’re working on industrial automation, motor drive circuits, power supply designs, or digital signal isolation, the IS181D is a versatile component that can meet your needs.

For sourcing and further assistance, feel free to contact us at ICRFQ. Now, go forth and let your creativity shine with the IS181D. Explore, experiment, and enjoy the journey of electronic innovation.

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