LCA126 Solid State Relay SPST-NO Equivalent & Substitute Parts

Part Overview

The LCA126 is a solid state relay (SSR) manufactured by IXYS Integrated Circuits Division, configured as a SPST-NO (Single Pole Single Throw - Normally Open) device in a 6-DIP package. This component switches AC and DC loads up to 250V with a maximum load current of 170mA and features a 1.2VDC input trigger voltage. The LCA126 is classified as obsolete, making identification of equivalent and substitute parts essential for ongoing system maintenance and new design implementations.

Substiute Parts

LCA126

IXYS Integrated Circuits DivisionIn Stock: 2788LCA126 Datasheet

Current PartRFQ

LCA127

LittelfuseIn Stock: 2239LCA127 Datasheet

DirectRFQ

LH1500AT

Vishay Semiconductor Opto DivisionIn Stock: 8757LH1500AT Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the LCA126 is determined by strict equivalence across the following critical parameters:

• Circuit configuration must remain SPST-NO (1 Form A)
• Package and pinout must be 6-DIP (0.300", 7.62mm) for direct board compatibility
• Output type must support both AC and DC switching
• Load voltage range must equal or exceed 0V ~ 250V
• Load current rating must meet or exceed 170mA
• Input voltage trigger must be compatible with 1.2VDC control signals
• Termination style must be PC Pin for through-hole mounting

The LCA127 and LH1500AT meet these substitution criteria with variations in performance characteristics that remain within acceptable operating parameters for this product category.

Parameter Comparison

Engineering Selection Recommendations

The LCA126 is obsolete and no longer available from the original manufacturer. Both substitute parts maintain the same 6-DIP package footprint and SPST-NO circuit configuration, ensuring direct board-level compatibility.

The LCA127 (Littelfuse) is the primary substitute, offering active product status with ROHS3 compliance. It provides superior on-state resistance (10 Ohms vs. 15 Ohms) and higher load current capability (200mA vs. 170mA) while maintaining identical input voltage and load voltage specifications.

The LH1500AT (Vishay Semiconductor Opto Division) is an alternative substitute with active product status and ROHS3 compliance. It extends the load voltage range to 350V and includes operating temperature specification (-40°C ~ 85°C) with approval agency certifications (cUR, DIN, FIMKO, UL). The input voltage is marginally higher at 1.25VDC, and load current is reduced to 150mA with increased on-state resistance (20 Ohms).

Both substitutes are available in active production with compliance certifications suitable for regulated applications.

Frequently Asked Questions (FAQ)

Q: Can the LCA127 directly replace the LCA126 without circuit modifications?

A: Yes. The LCA127 maintains identical package geometry (6-DIP), circuit configuration (SPST-NO), input voltage (1.2VDC), and load voltage range (0V ~ 250V). The improved performance characteristics (lower on-state resistance, higher current rating) are backward compatible.

Q: What is the key difference between the LCA127 and LH1500AT substitutes?

A: The LCA127 matches the original load voltage specification (250V) with higher current capacity (200mA). The LH1500AT extends load voltage capability to 350V but reduces current capacity to 150mA and increases on-state resistance. Selection depends on whether the application requires higher voltage tolerance or higher current capacity.

Q: Are both substitutes suitable for new designs?

A: Yes. Both the LCA127 and LH1500AT carry active product status and ROHS3 compliance, making them appropriate for new production designs. The LH1500AT additionally provides operating temperature range and multiple approval agency certifications.

Q: Does the 1.25VDC input voltage of the LH1500AT affect compatibility with 1.2VDC control circuits?

A: The 0.05VDC difference is within typical control circuit tolerances. However, applications with marginal input voltage headroom should prioritize the LCA127, which maintains the exact 1.2VDC specification.

Q: What packaging options are available for these substitutes?

A: The LCA127 is supplied in Tube packaging. The LH1500AT is supplied in Tube packaging. Both maintain the 6-DIP through-hole form factor for direct board compatibility.