SPA4191 Equivalent & Substitute Parts

Part Overview

The SPA4191 is a solid-state relay (SSR) manufactured by Sensata Technologies, configured as a SPST-NO (Single Pole Single Throw - Normally Open) device with 1 A load current capacity and a load voltage range of 20 V to 140 V. This component is classified as obsolete, making identification of functionally equivalent alternatives essential for ongoing system maintenance and new design implementations where similar performance characteristics are required.

Substiute Parts

SPA4191

Sensata TechnologiesIn Stock: 3076SPA4191 Datasheet

Current PartRFQ

ASO241

Sensata-CrydomIn Stock: 1255ASO241 Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the SPA4191 is determined by the following critical parameters:

• Circuit Configuration: Must be SPST-NO (1 Form A) to maintain identical switching topology
• Package / Case: Must be 4-SIP to ensure mechanical and electrical compatibility with existing PCB layouts
• Mounting Type: Must be Through Hole to match board assembly requirements
• Termination Style: Must be PC Pin for direct connection compatibility
• Output Type: Must be AC with Zero Cross functionality to preserve load switching characteristics
• Load Voltage Range: Must encompass or exceed the 20 V ~ 140 V operating window
• Load Current: Must meet or exceed 1 A minimum requirement

The ASO241 satisfies all these criteria while offering enhanced specifications in load voltage range (12 V ~ 280 V) and load current capacity (1.5 A), making it a direct functional equivalent with extended operational capability.

Parameter Comparison

Engineering Selection Recommendations

The ASO241 is the qualified substitute for the SPA4191 based on the following engineering criteria:

Functional Equivalence: Both components share identical circuit configuration (SPST-NO), output type (AC, Zero Cross), package format (4-SIP), and termination style (PC Pin). This ensures direct compatibility with existing designs without PCB modification.

Enhanced Specifications: The ASO241 provides superior load voltage range (12 V ~ 280 V versus 20 V ~ 140 V) and increased load current capacity (1.5 A versus 1 A), offering extended operational margins for the same physical footprint.

Product Status and Compliance: The ASO241 maintains active product status with ROHS3 compliance certification, ensuring long-term availability and regulatory alignment. The SPA4191's obsolete status necessitates transition to an actively manufactured alternative.

Manufacturer Continuity: Both components originate from the Sensata family of manufacturers (Sensata Technologies and Sensata-Crydom), maintaining design philosophy and reliability standards.

Frequently Asked Questions (FAQ)

Q: Can the ASO241 be used as a direct replacement for the SPA4191 without PCB modifications?

A: Yes. Both components use identical 4-SIP package format, Through Hole mounting, and PC Pin termination. No PCB layout changes are required for mechanical or electrical integration.

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

A: The ASO241 offers wider load voltage range (12 V ~ 280 V versus 20 V ~ 140 V) and higher load current capacity (1.5 A versus 1 A). The ASO241 also specifies input voltage requirements (4 V ~ 10 VDC) and includes ROHS3 compliance certification.

Q: Is the ASO241 suitable for applications originally designed for the SPA4191?

A: Yes, provided the application's load voltage and current requirements fall within the ASO241's specifications. The enhanced ratings of the ASO241 make it suitable for all applications within the SPA4191's original operating envelope.

Q: What is the significance of the "Zero Cross" output type?

A: Zero Cross switching ensures the relay activates and deactivates at AC voltage zero-crossing points, minimizing electromagnetic interference and reducing stress on connected loads. Both components share this functionality.

Q: Why is the SPA4191 listed as obsolete?

A: Obsolete status indicates the manufacturer has discontinued production. The ASO241 represents the current-generation equivalent from the Sensata product family, offering improved specifications and ongoing availability.

Q: Are there any compliance or certification differences between these parts?

A: The ASO241 includes ROHS3 compliance certification, ensuring compliance with current environmental and hazardous substance regulations. The SPA4191's compliance status is not specified in available documentation.