ELD211(TB)

Overview

The ELD211(TB) is a dual-channel phototransistor optocoupler manufactured by Everlight Electronics. It features an infrared emitting diode optically coupled to two NPN phototransistors with bases, housed in an 8-pin SOP package. The device provides electrical isolation with a rated insulation voltage of 3750 Vrms. It offers a minimum current transfer ratio greater than 20%. The component is designed for surface mount assembly and supports standard reflow soldering processes.

Feature Summary

• Dual-channel configuration integrating two independent signal paths within a single compact package
• High-voltage isolation capability rated at 3750 Vrms for safe circuit separation
• Integrated base terminals on phototransistors allowing for adjustable sensitivity and speed control
• Surface-mount SOP-8 packaging compatible with automated placement equipment

Applications

• Industrial control systems requiring signal isolation
• Data communication interfaces needing galvanic separation
• Power supply feedback loops for voltage regulation
• Microcontroller input/output isolation circuits

Procurement Notes

Verify the specific suffix designation (TA vs TB) during procurement, as it typically indicates variations in Current Transfer Ratio bins or reel packaging specifications rather than functional differences. Confirm moisture sensitivity level handling requirements if storage conditions exceed manufacturer limits. Ensure the ordering part number matches the required isolation voltage and channel count specifications for the target application design.

Selection Notes

Select this component when dual-channel isolation is required in a space-constrained design. The integrated base pins allow designers to optimize switching speed versus gain trade-offs by adding external resistors. Compare against single-channel alternatives if only one isolated path is needed to reduce board area. Verify that the 3750 Vrms rating meets the safety standards applicable to the end equipment.

Part Context

ELD211 belongs to Everlight's family of dual-channel transistor output optocouplers. Variants such as ELD205, ELD206, and ELD207 share similar physical packages but differ primarily in their specified Current Transfer Ratio ranges. This series is engineered for general-purpose isolation tasks where moderate speed and high reliability are prioritized over high-speed digital signaling capabilities found in logic-output variants.

Replacement Considerations

Direct pin-compatible substitutes may include other dual-channel transistor optocouplers from different manufacturers, provided they meet the 3750 Vrms isolation and SOP-8 footprint requirements. Verify CTR ranges and propagation delays before substitution. Cross-reference with ELD211(TA) if binning differences are not critical to the design.