1458 Optocoupler — Datasheet

* Input side
V_IN ----|>|----+---- R_IN ---- GND
          LED   |
                |
               ( )  Pull‑up resistor R_PULL (10 kΩ) to V_CC
                |
                +----> V_OUT (collector)
                |
               ( )  Emitter to GND

Assuming your "1458 optocoupler" is a standard DIP-6, here is the pinout (identical to 4N35, PC817, and most general-purpose types):

        Top View (Notch facing left or up)
        ---- Notch ----
       | 1  o      o 6 |
       | 2  o      o 5 |
       | 3  o      o 4 |
        ------------

Typical Wiring for Logic Isolation:

The first page tells you the physical format. Look for:

Since no "1458 optocoupler" exists, we analyze the widely available 4N35 from Vishay or ON Semiconductor.

Assume a mistaken desire to use a "1458 optocoupler" – instead, we select the 4N35.

The 1458 optocoupler is a robust component essential for noise reduction and safety in circuit design. By understanding the datasheet parameters—specifically Forward Voltage, CTR, and Isolation Voltage—you can safely implement it in your designs to bridge the gap between low-power logic and high-power peripherals. 1458 optocoupler datasheet

Just remember to double-check that you haven't accidentally picked up a 1458 Op-Amp!

Have you used this component in a project? Are you having trouble identifying a specific marking? Drop a comment below with a photo or description!

, allowing for seamless integration into both 3.3V and 5V logic systems. Low Drive Power : Requires low forward current ( cap I sub cap F

), which reduces the power consumption of the driving circuit. Hermetic Packaging : Typically housed in an SOP-8 hermetically sealed package

, which protects internal components from moisture and contaminants in harsh environments. TTL Compatibility * Input side V_IN ----|>|----+---- R_IN ---- GND

: The output is compatible with standard Transistor-Transistor Logic (TTL), simplifying its use with microcontrollers and digital circuits. Performance Characteristics Typical Value / Description Propagation Delay Supply Voltage ( cap V sub cap C cap C end-sub 3.0V to 5.5V Package Type SOP-8 (Hermetically Sealed) Output Type Open Collector Typical Applications The HCPL-1458 is frequently used for Microcontroller Interfacing

to protect sensitive MCUs from high-voltage spikes. Other common uses include: Isolated Line Receivers

: For high-speed data communication across different ground planes. Motor Control

: Providing safe isolation between low-voltage control signals and high-voltage power stages like IGBTs and MOSFETs Switching Power Supplies : Used in feedback loops to maintain isolation. Manufacturer Resources For full technical details, you can refer to the official HCPL-1458 Datasheet

provided by manufacturers like Broadcom (formerly Avago/Agilent). Heisener Electronics or a specific circuit example for this component? MC1458 - STMicroelectronics Assuming your "1458 optocoupler" is a standard DIP-6,

CTR is calculated as: CTR = (IC / IF) * 100%

A datasheet will show CTR graphs. For a generic optocoupler, CTR decreases as temperature rises and as the optocoupler ages (over years). For reliable digital communication, ensure your IC is at least 2x the required input current of your receiving chip.

How do you actually use this? Here is a classic example of interfacing a 5V microcontroller with a 12V load.

The Goal: Turn on a 12V relay using a 5V Arduino.

In this setup, when the Arduino sends a HIGH signal, the internal LED lights up. The phototransistor detects this light and closes the circuit, allowing the 12V current to flow through the relay. The Arduino remains electrically isolated from the 12V circuit.