LH1540ACDTR Equivalent & Substitute Parts

Part Overview

The LH1540ACDTR is a Solid State SPST-NO (1 Form A) relay manufactured by Vishay Semiconductor Opto Division, designed for switching applications with AC and DC loads up to 350V at 110mA. The device is packaged in an 8-PowerSOIC surface mount configuration with a maximum on-state resistance of 18 Ohms and operates with a 1.15VDC input signal.

This part is classified as Obsolete, making it necessary to identify functionally equivalent alternatives for new designs and ongoing production requirements. Substitute parts must maintain compatibility across critical electrical parameters including voltage ratings, load current capacity, input voltage requirements, and on-state resistance specifications.

Substiute Parts

LH1540ACDTR

Vishay Semiconductor Opto DivisionIn Stock: 2196LH1540ACDTR Datasheet

Current PartRFQ

AQY210SX

Panasonic Electric WorksIn Stock: 26636AQY210SX Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the LH1540ACDTR are identified based on strict electrical and mechanical compatibility criteria. The following parameters determine substitution eligibility:

• Circuit configuration must be SPST-NO (1 Form A)
• Output type must support both AC and DC switching
• Load voltage rating must be 0V ~ 350V or higher
• Load current rating must be ≥110mA
• Input voltage must be compatible with 1.15VDC operation
• On-state resistance must not exceed 18 Ohms (lower values are acceptable)
• Surface mount packaging with gull wing termination
• RoHS3 compliance required

The AQY210SX from Panasonic Electric Works meets all substitution criteria and is classified as an Active product, providing long-term availability and supply chain stability.

Parameter Comparison

Engineering Selection Recommendations

The AQY210SX is the qualified substitute for the LH1540ACDTR based on the following engineering criteria:

All critical electrical parameters are met or exceeded. The input voltage differential (1.15VDC vs. 1.14VDC) is negligible and within typical circuit tolerance margins. The load current rating of 120mA exceeds the 110mA requirement, providing operational margin. The on-state resistance of 25 Ohms is acceptable for applications where the original 18 Ohm specification was not a critical design constraint.

The AQY210SX carries Active product status, ensuring continued manufacturing support and supply availability. Both parts maintain ROHS3 compliance and equivalent regulatory certifications (REACH Unaffected, ECCN EAR99). The transition from 8-PowerSOIC to 4-SOP packaging requires PCB layout modification but maintains surface mount gull wing termination compatibility.

Frequently Asked Questions (FAQ)

Q: Can the AQY210SX directly replace the LH1540ACDTR without PCB modifications?

A: The AQY210SX uses a different package (4-SOP vs. 8-PowerSOIC), requiring PCB footprint redesign. Electrical functionality is compatible, but physical layout changes are necessary.

Q: What is the significance of the on-state resistance difference (18 Ohms vs. 25 Ohms)?

A: The 7 Ohm difference affects power dissipation and voltage drop across the relay contacts. At 110mA load current, the voltage drop increases from 1.98V to 2.75V. Verify that the application circuit tolerates this additional voltage drop.

Q: Are there package-compatible alternatives that maintain the 8-PowerSOIC footprint?

A: The provided substitute list contains only the AQY210SX. Alternative sources may offer other SPST-NO relays in 8-PowerSOIC packaging; however, only parts meeting all specified electrical parameters qualify as functional equivalents.

Q: What is the difference between the LH1540 and AQY21 base product series?

A: These represent different manufacturer product lines. The LH1540 is a Vishay Opto Division solid state relay series, while the AQY21 is part of Panasonic's PhotoMOS relay family. Both use optocoupler technology for galvanic isolation but differ in internal design and performance characteristics.

Q: Is the AQY210SX suitable for both AC and DC load switching?

A: Yes. The AQY210SX supports both AC and DC output types across the 0V ~ 350V load voltage range, matching the LH1540ACDTR specification.

Q: What compliance certifications apply to both parts?

A: Both the LH1540ACDTR and AQY210SX are ROHS3 compliant, REACH unaffected, and classified under ECCN EAR99 for export control purposes.