VO4256H Optoisolator Triac Output Equivalent & Substitute Parts

Part Overview

The VO4256H is a 5.3kV isolation optoisolator with triac output manufactured by Vishay Semiconductor Opto Division in a 6-DIP through-hole package. This component is classified as obsolete, making equivalent substitute parts necessary for new designs and ongoing production support. The VO4256H provides galvanic isolation for AC switching applications with a single triac output channel and 5300Vrms isolation voltage rating.

Substiute Parts

VO4256H

Vishay Semiconductor Opto DivisionIn Stock: 1121VO4256H Datasheet

Current PartRFQ

EL3051

Everlight Electronics Co LtdIn Stock: 52485EL3051 Datasheet

MFR RecommendedRFQ

EL3052

Everlight Electronics Co LtdIn Stock: 151994EL3052 Datasheet

MFR RecommendedRFQ

EL3053

Everlight Electronics Co LtdIn Stock: 17973EL3053 Datasheet

MFR RecommendedRFQ

FOD420

onsemiIn Stock: 6010FOD420 Datasheet

MFR RecommendedRFQ

FOD4216

onsemiIn Stock: 4738FOD4216 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the VO4256H is determined by the following critical parameters:

• Package compatibility: 6-DIP (0.300", 7.62mm) through-hole mounting
• Output type: Triac output configuration
• Isolation voltage: Minimum 5000Vrms (VO4256H specifies 5300Vrms)
• Number of channels: Single channel
• Operating temperature range: -55°C ~ 100°C
• Off-state voltage: 600 V
• RoHS compliance: ROHS3 Compliant

The substitute parts listed below meet these core requirements. Variations in LED trigger current (Ift), on-state current (It), and static dV/dt ratings reflect different design specifications within the same functional category and do not preclude substitution when application requirements are satisfied.

Parameter Comparison

Engineering Selection Recommendations

All listed substitute parts are active products with current manufacturing support, addressing the obsolescence status of the VO4256H. Selection among substitutes depends on application-specific requirements:

Everlight EL3051, EL3052, EL3053: These parts maintain compatibility with the VO4256H across all core parameters. The EL305x series differs in LED trigger current specifications (15mA, 10mA, and 5mA respectively) and lower static dV/dt rating (1kV/µs). These parts carry CSA, DEMKO, FIMKO, NEMKO, SEMKO, and UL certifications.

onsemi FOD420 and FOD4216: These parts provide higher static dV/dt performance (10kV/µs) and lower LED trigger current (2mA and 1.3mA respectively). The FOD4216 offers the lowest trigger current specification. Both carry cUL, FIMKO, and UL certifications. Forward current specifications are lower (30mA maximum) compared to the VO4256H and EL305x series.

The VO4256H specifies 300mA on-state current, which exceeds the 100mA maximum of the EL305x series. Applications requiring this higher current rating should evaluate whether the onsemi FOD420 or FOD4216 specifications meet load requirements, as on-state current is not specified for these parts.

Frequently Asked Questions (FAQ)

Q: Can the EL3051, EL3052, or EL3053 directly replace the VO4256H?

A: These parts are mechanically and electrically compatible within the 6-DIP package and share the same isolation voltage class (5000Vrms minimum). Pin configuration and triac output topology are identical. Differences in LED trigger current and static dV/dt do not prevent substitution when application requirements are satisfied by the substitute part specifications.

Q: What is the difference between EL3051, EL3052, and EL3053?

A: These three parts differ only in LED trigger current (Ift) maximum ratings: EL3051 at 15mA, EL3052 at 10mA, and EL3053 at 5mA. All other electrical and mechanical parameters are identical. Selection depends on the input drive circuit capability and desired trigger sensitivity.

Q: How do the onsemi FOD420 and FOD4216 differ from the Everlight EL305x series?

A: The FOD420 and FOD4216 provide higher static dV/dt performance (10kV/µs versus 1kV/µs) and lower LED trigger current specifications. However, forward current is limited to 30mA maximum compared to 60mA for the EL305x series. On-state current is not specified for the onsemi parts. These differences may affect circuit design and should be evaluated against application requirements.

Q: Is the 5000Vrms isolation voltage of substitute parts sufficient for applications designed for the VO4256H's 5300Vrms rating?

A: Isolation voltage is a specified minimum rating. Applications designed for 5300Vrms isolation should confirm that 5000Vrms meets the required safety margin and regulatory compliance for the intended use. This determination is application-specific and must be made by the design engineer.

Q: Are all substitute parts RoHS3 compliant?

A: Yes. The VO4256H and all listed substitute parts (EL3051, EL3052, EL3053, FOD420, FOD4216) are ROHS3 compliant.

Q: What certifications do these parts carry?

A: The Everlight EL305x series carries CSA, DEMKO, FIMKO, NEMKO, SEMKO, and UL certifications. The onsemi FOD420 and FOD4216 carry cUL, FIMKO, and UL certifications. The original VO4256H carries cUR, FIMKO, and UR certifications. Certification requirements for your application should be verified against the substitute part documentation.

Q: Can I use FOD420 or FOD4216 in place of the EL305x series?

A: Both part families meet the core substitution criteria (6-DIP package, triac output, 5000Vrms isolation, single channel, -55°C to 100°C operating range). However, differences in forward current (30mA versus 60mA) and unspecified on-state current for the onsemi parts require circuit-level evaluation. Direct substitution is not automatic and depends on application requirements.