LH1546AD Solid State Relay - Equivalent & Substitute Parts

Part Overview

The LH1546AD is a solid state relay (SSR) manufactured by Vishay Semiconductor Opto Division, configured as a SPST-NO (Single Pole Single Throw - Normally Open) relay in a 4-DIP package. This component is designed for switching applications with AC and DC loads up to 350V at 120mA maximum load current. The LH1546AD is classified as obsolete, making identification of functionally equivalent alternatives necessary for ongoing system maintenance and new design implementations.

Substiute Parts

LH1546AD

Vishay Semiconductor Opto DivisionIn Stock: 1273LH1546AD Datasheet

Current PartRFQ

AQY210HL

Panasonic Electric WorksIn Stock: 29611AQY210HL Datasheet

MFR RecommendedRFQ

PVT412PBF

Infineon TechnologiesIn Stock: 2622PVT412PBF Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the LH1546AD is determined by the following critical parameters:

• Circuit configuration must be SPST-NO (1 Form A)
• Output type must support both AC and DC switching
• Input voltage must be compatible with 1.2VDC control signal
• Load voltage rating must meet or exceed 0V ~ 350V range
• Load current capability must be at least 120mA
• On-state resistance must not exceed 28 Ohms
• Package must be through-hole DIP format
• RoHS3 compliance required

The identified substitute parts meet these criteria with the following considerations:

AQY210HL (Panasonic Electric Works): Meets all critical parameters with active product status and improved on-state resistance (25 Ohms). Package remains 4-DIP format with identical mechanical footprint.

PVT412PBF (Infineon Technologies): Exceeds load voltage rating (400V) and load current capability (140mA). Package differs to 6-DIP format, requiring PCB layout modification. On-state resistance (27 Ohms) remains within acceptable range.

Parameter Comparison

Engineering Selection Recommendations

AQY210HL is the preferred direct substitute for the LH1546AD. Both components share identical package geometry (4-DIP), electrical specifications within the required range, and active product status ensures long-term availability. The AQY210HL demonstrates improved on-state resistance (25 Ohms vs. 28 Ohms), providing enhanced performance characteristics. RoHS3 compliance and REACH unaffected status maintain regulatory alignment.

PVT412PBF functions as a capable alternative with enhanced electrical ratings (400V load voltage, 140mA load current). However, the 6-DIP package format requires PCB layout modification and cannot be used as a direct pin-compatible replacement. Selection of PVT412PBF is appropriate only when PCB redesign is feasible and the enhanced electrical specifications provide system-level benefits.

Both substitute parts maintain ROHS3 compliance and REACH unaffected status, consistent with the original LH1546AD specifications.

Frequently Asked Questions (FAQ)

Q: Can AQY210HL be used as a direct replacement for LH1546AD without PCB modification?

A: Yes. The AQY210HL maintains identical 4-DIP package dimensions (0.300", 7.62mm) and pin configuration, enabling direct substitution without PCB layout changes.

Q: What is the primary difference between AQY210HL and PVT412PBF?

A: AQY210HL provides pin-compatible replacement with identical package format. PVT412PBF offers higher load voltage (400V) and current (140mA) ratings but requires 6-DIP package accommodation, necessitating PCB redesign.

Q: Are both substitute parts suitable for applications requiring the original 350V load voltage specification?

A: Yes. Both AQY210HL (350V rating) and PVT412PBF (400V rating) meet or exceed the 350V load voltage requirement of the LH1546AD.

Q: What is the input voltage compatibility between LH1546AD and its substitutes?

A: LH1546AD and PVT412PBF both require 1.2VDC input. AQY210HL operates at 1.14VDC, which is compatible with standard 1.2VDC control circuits with minimal voltage margin difference.

Q: Do the substitute parts maintain the same on-state resistance characteristics?

A: On-state resistance values are comparable across all three parts: LH1546AD (28 Ohms max), AQY210HL (25 Ohms max), and PVT412PBF (27 Ohms max). All values remain within acceptable operating parameters for equivalent thermal and switching performance.

Q: Are regulatory certifications maintained with substitute parts?

A: Yes. Both AQY210HL and PVT412PBF maintain ROHS3 compliance and REACH unaffected status, consistent with the original LH1546AD specifications.