LCA125 Solid State Relay - Equivalent & Substitute Parts

Part Overview

The LCA125 is an IXYS OptoMOS® solid state relay (SSR) configured as a SPST-NO (Single Pole Single Throw - Normally Open) switching device. This 6-DIP through-hole component is designed for AC and DC load switching applications with a maximum load voltage of 350V and 170mA current capacity. The device is currently in active production status with full RoHS3 compliance and unlimited moisture sensitivity rating. Substitute parts are identified when equivalent electrical performance and mechanical compatibility are required due to component availability, procurement lead times, or inventory constraints.

Substiute Parts

LCA125

IXYS Integrated Circuits DivisionIn Stock: 20420LCA125 Datasheet

Current PartRFQ

LH1500AT

Vishay Semiconductor Opto DivisionIn Stock: 8757LH1500AT Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the LCA125 is determined by strict equivalence in the following critical parameters:

• Package and Pinout: 6-DIP (0.300", 7.62mm) with PC pin termination for direct PCB compatibility
• Circuit Configuration: SPST-NO (1 Form A) topology for identical switching functionality
• Load Voltage Range: 0V ~ 350V maximum operating envelope
• Input Control Voltage: Nominal 1.2VDC to 1.25VDC for gate drive compatibility
• Output Type: AC and DC load switching capability
• Mounting Method: Through-hole assembly on standard PCB layouts
• Compliance Standards: RoHS3 compliance and MSL 1 rating for manufacturing process compatibility

The LH1500AT from Vishay Semiconductor Opto Division meets all substitution criteria within the allowed parameter tolerances for this product category.

Parameter Comparison

Engineering Selection Recommendations

Both the LCA125 and LH1500AT are active production components with full RoHS3 compliance and MSL 1 ratings, ensuring compatibility with standard manufacturing processes and long-term availability. The LH1500AT operates within the specified load voltage range and maintains the same package footprint and pinout configuration.

The LH1500AT is rated for 150mA maximum load current compared to the LCA125's 170mA rating, and exhibits a maximum on-state resistance of 20 Ohms versus 16 Ohms for the primary part. These parameter differences must be evaluated against specific application load requirements. The input voltage differential of 0.05VDC (1.2V vs. 1.25V) is within standard gate drive tolerances for optoisolated SSR devices.

Selection between these components should be based on application load current requirements, acceptable on-state voltage drop, and component availability at the time of procurement.

Frequently Asked Questions (FAQ)

Q: Can the LH1500AT directly replace the LCA125 in existing PCB designs?

A: Yes, the LH1500AT is pin-compatible and footprint-compatible with the LCA125. Both devices use the 6-DIP (0.300", 7.62mm) package with PC pin termination. No PCB layout modifications are required for mechanical substitution.

Q: What are the electrical differences between these two parts?

A: The LH1500AT has a lower maximum load current rating (150mA vs. 170mA) and higher on-state resistance (20 Ohms vs. 16 Ohms). The input voltage requirement is slightly higher (1.25VDC vs. 1.2VDC). These differences must be evaluated against your specific application load profile.

Q: Are both parts suitable for AC and DC load switching?

A: Yes, both the LCA125 and LH1500AT support AC and DC output switching across the 0V to 350V load voltage range.

Q: Do both parts meet the same compliance standards?

A: Yes, both components are RoHS3 compliant with MSL 1 (Unlimited) moisture sensitivity rating. Both are currently in active production status.

Q: What is the significance of the input voltage difference?

A: The 0.05VDC difference (1.2V vs. 1.25V) represents a 4% variation in gate drive voltage. This is within standard tolerance for optoisolated SSR gate drive circuits and does not affect functional compatibility in typical applications.

Q: Which part should I select for high-current applications?

A: The LCA125 is rated for 170mA load current and should be selected for applications requiring the full current capacity. The LH1500AT is suitable for applications with load currents up to 150mA.