A1458 Optocoupler Datasheet =link= 💯

The output phototransistor is an "open collector." It acts like a switch to ground. To get a logic signal, you need a pull-up resistor (usually 1kΩ to 10kΩ) connected to the Collector pin.

: Features a high common-mode transient immunity (CMR) of at least 15,000 V/μs a1458 optocoupler datasheet

Whether you are building a smart home switch or a power supply, the A1458 is a reliable, cost-effective component to keep in your parts bin. The output phototransistor is an "open collector

You need a resistor in series with the LED. You need a resistor in series with the LED

In micro-controller units (MCUs) or programmable logic controllers (PLCs), high external voltages from motors or relays can leak back into delicate logic systems. The A1458 acts as a barrier, allowing the MCU to transmit commands safely via infrared light. II. Switching Power Supplies (SMPS)

This configuration uses to improve noise performance and signal integrity.

Assume you want a forward current ( IFcap I sub cap F ) of 10mA to ensure a solid CTR.From the datasheet,