EL851

Overview

The EL851 is a four-pin DIP high-voltage phototransistor optocoupler manufactured by Everlight Electronics. It features a single channel configuration with a phototransistor output. Key electrical parameters include a maximum collector-emitter voltage of 35 V and a maximum collector current of 80 mA. The device supports a forward current of 60 mA with a forward voltage of 1.4 V. It offers an insulation voltage of 5000 Vrms and a power dissipation of 200 mW. The current transfer ratio ranges from 50% to 600%. Operating temperatures span from -55°C to +110°C, with rise and fall times specified at 4 µs and 18 µs respectively.

Feature Summary

• High isolation voltage capability for safe signal transmission between isolated circuits
• Phototransistor output design suitable for general-purpose switching applications
• Wide operating temperature range ensuring reliability in diverse environmental conditions

Applications

• General purpose signal isolation
• Switching power supply feedback loops
• Microprocessor system interface circuits

Procurement Notes

Verify the specific suffix codes on the component marking to ensure compatibility with required packaging or lead-free standards. Confirm that the supplier provides official datasheets matching the exact part number variant. Check for end-of-life status as some distributors indicate obsolescence for certain variants. Ensure the source is an authorized distributor to guarantee authenticity and traceability of the electronic components.

Selection Notes

Select this component when high isolation voltage is required alongside moderate speed switching capabilities. The phototransistor output type is appropriate for applications needing higher gain compared to standard photodiode outputs. Consider the 4-pin DIP package for through-hole mounting requirements. Evaluate the current transfer ratio specifications against the load requirements to ensure sufficient drive capability for the connected circuitry.

Part Context

The EL851 belongs to the family of high-voltage phototransistor optocouplers produced by Everlight Electronics. These devices are designed to provide electrical isolation between input and output circuits while transmitting digital or analog signals. The product line typically includes variations with different output types such as photodarlington configurations for higher sensitivity.

Replacement Considerations

Check for direct pin-compatible substitutes within the same manufacturer's portfolio that match the 35V collector-emitter voltage and 80mA collector current ratings. Verify that alternative components offer comparable insulation voltage and current transfer ratio specifications to maintain circuit performance integrity.