IS357

Overview

The IS357 is a high-density mounting phototransistor optically coupled isolator manufactured by Isocom Components. It consists of an infrared light-emitting diode and an NPN silicon phototransistor housed in a space-efficient dual in-line plastic package. The device provides electrical isolation between input and output circuits, ensuring signal integrity while preventing noise interference. Key specifications include a minimum current transfer ratio of 600% and an isolation voltage of 3.75 kV RMS with a peak voltage of 5.3 kV. All electrical parameters are subjected to 100% testing to ensure reliability. This component serves as a drop-in replacement for the Sharp PC355, facilitating easy integration into existing designs requiring robust optical isolation.

Feature Summary

• High current transfer ratio ensures efficient signal transmission
• Space-efficient dual in-line plastic package design
• Complete electrical parameter verification through 100% testing
• Compatible drop-in replacement for established industry components

Applications

• Computer terminals
• Industrial systems controllers
• Measuring instruments
• Signal transmission between systems of different potentials and impedances

Procurement Notes

Verify that the specific order matches the IS357 designation from Isocom Components. Confirm the package type corresponds to the standard dual in-line plastic configuration. Ensure the supplier provides documentation confirming the 100% electrical parameter test results. Check for compatibility requirements if replacing legacy Sharp PC355 units in existing hardware assemblies.

Selection Notes

Select this component when high density mounting is required alongside reliable optical isolation. The high current transfer ratio makes it suitable for applications demanding strong signal coupling across the isolation barrier. Consider its use in environments where impedance matching between different system potentials is necessary. Verify that the plastic package meets the thermal and mechanical constraints of the target application.

Part Context

The IS357 belongs to the family of phototransistor optocouplers designed for general-purpose isolation tasks. It shares functional similarities with other high-density optocouplers but distinguishes itself through its specific current transfer characteristics and package form factor. As a direct replacement for the Sharp PC355, it maintains pinout and electrical compatibility, allowing for seamless upgrades or substitutions in established electronic designs without requiring circuit board modifications.

Replacement Considerations

The IS357 is explicitly documented as a drop-in replacement for the Sharp PC355. When substituting, verify that the existing design accommodates the plastic package dimensions and that the isolation voltage ratings meet or exceed the original system requirements.