A1458 Optocoupler Datasheet May 2026

Note: This is a developer-generated technical text based on standard optocoupler specifications (similar to 4N35, PC817, or MOC302x families). For a real A1458, please check the manufacturer’s official datasheet.

A1458 Optocoupler Datasheet: A Complete Technical Deep Dive

Introduction

In the world of electronics, isolation is paramount. Whether you are designing a switch-mode power supply (SMPS), a microcontroller interface for industrial machinery, or a safety system for a medical device, the optocoupler (also known as an opto-isolator) is a critical component. Among the myriad of options available, the A1458 optocoupler has gained recognition for its balance of speed, current transfer ratio (CTR), and isolation voltage.

However, finding a consolidated, detailed explanation of the A1458 optocoupler datasheet can be challenging. This article serves as a complete guide to the A1458. We will dissect every section of the datasheet—from absolute maximum ratings to switching characteristics—providing engineers, hobbyists, and students with the knowledge needed to integrate this component effectively. a1458 optocoupler datasheet

Note: The A1458 is often associated with a general-purpose phototransistor output optocoupler, similar in class to the 4N35 or PC817 but with specific parametric differences. Always refer to the manufacturer’s official datasheet for the exact revision you are using (e.g., from Vishay, Everlight, or a generic Chinese brand). This article synthesizes typical specifications for the A1458 series.

Mechanical & pinout (general)

4 pins: 1 = LED anode, 2 = LED cathode, 3 = transistor collector, 4 = transistor emitter (pin numbering may vary—verify actual part drawing).
Typical DIP footprint; check exact mechanical drawing for lead spacing and package dimensions.

Part 8: Layout and Design Guidelines

Based on recommendations in the A1458 optocoupler datasheet and industry best practices: Note: This is a developer-generated technical text based

Keep Input and Output Separate: Do not route high-voltage or noisy traces under the optocoupler. Maintain a physical and electrical gap.
Creepage on PCB: On the PCB, ensure at least 4 mm clearance between input-side copper and output-side copper (more for >250V applications).
Slotted PCB: For high isolation (>5kV), consider a slot in the PCB under the optocoupler.
Bypass Capacitors: Place a 0.1 μF ceramic capacitor near the output VCC and ground (if using external pull-up) to reduce switching noise.
Current Limit: Never drive the LED directly from a voltage source without a series resistor. A small change in voltage leads to a large change in current – potentially destructive.

6. Electrical Characteristics (Ta = 25°C)

| Parameter | Symbol | Test Condition | Min | Typ | Max | Unit | |--------------------------|--------|-------------------------|-----|-----|-----|-------| | LED forward voltage | VF | IF = 20 mA | 1.1 | 1.2 | 1.4 | V | | LED reverse current | IR | VR = 6 V | - | - | 10 | µA | | Collector dark current | ICEO | VCE = 20 V, IF = 0 | - | - | 100 | nA | | Current transfer ratio | CTR | IF = 5 mA, VCE = 5V | 50 | 300 | 600 | % | | Collector-emitter sat. | VCE(sat)| IF = 10 mA, IC = 2 mA | - | 0.2 | 0.4 | V | | Isolation resistance | RISO | VIO = 500 Vdc | 10¹¹| - | - | Ω | | Capacitance (input-output)| CIO | f = 1 MHz | - | 1.0 | - | pF |

3. Misread Date Codes or Logos

If the part physically has "A1458" printed on it: A1458 Optocoupler Datasheet: A Complete Technical Deep Dive

"A" Logo: It might be an Avago (now Broadcom) or Vishay part. However, standard Avago part numbers usually follow formats like HCPL-xxxx or ACPL-xxxx.
Date Code: A1458 might be a date code (Year 2014, Week 58) rather than the part number. In this case, look for other markings like "817" (PC817) or "357" (PC357) printed often on a separate line.

How to Read a Typical Circuit from the Datasheet

Page 3 of the official a1458 optocoupler datasheet usually contains a "Test Circuit" diagram. Here is the standard configuration for digital signal isolation:

Schematic Walkthrough:

Input Side: Apply a 5V logic signal. A current-limiting resistor (Rin) is placed in series with Pin 1. Formula: Rin = (Vin – VF) / IF. For Vin=5V, IF=10mA, and VF=1.2V → Rin = (5-1.2)/0.01 = 380Ω (Use 390Ω standard).
Output Side: Connect a pull-up resistor (Rpullup) from Pin 4 (Collector) to VCC (e.g., 5V or 24V). Pin 3 goes to GND.
Operation: When the LED is ON, the phototransistor conducts, pulling the output LOW. When the LED is OFF, the output is pulled HIGH by Rpullup.