CS337 Solid State Relay SPST-NO Equivalent & Substitute Parts

Part Overview

The CS337 is a solid state relay (SSR) manufactured by Coto Technology in the COTOMOS™ series. This component is a Surface Mount SPST-NO (Single Pole Single Throw, Normally Open) relay configured as 1 Form A x 2 in an 8-SMD package. The CS337 is rated for 360 mA load current at 0–60 V output voltage with a control input of 1.37 VDC.

The CS337 has reached obsolete product status. Locating equivalent or substitute components is necessary to support ongoing maintenance, repair, and new design requirements where this relay specification remains applicable.

Substiute Parts

CS337

Coto TechnologyIn Stock: 852CS337 Datasheet

Current PartRFQ

C347S

Coto TechnologyIn Stock: 2230C347S Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the CS337 is determined by the following critical parameters:

Functional Compatibility Criteria:

• Identical circuit configuration: SPST-NO (1 Form A) x 2
• Identical control input voltage: 1.37 VDC
• Identical output type: AC, DC capable
• Identical mounting type: Surface Mount with Gull Wing termination
• Identical manufacturer series: COTOMOS™

Performance Compatibility Criteria:

• Load voltage range must encompass or exceed the original 0–60 V specification
• Load current rating must equal or exceed 360 mA
• On-state resistance must be equal to or lower than 1.6 Ohms

Compliance Criteria:

• RoHS3 compliance required
• Moisture Sensitivity Level 2 or better
• REACH Unaffected status

The C347S meets all functional, performance, and compliance criteria and is therefore a valid substitute for the CS337.

Parameter Comparison

Engineering Selection Recommendations

The C347S is a valid substitute for the CS337 based on the following engineering criteria:

Functional Equivalence: Both components share identical circuit configuration (SPST-NO 1 Form A x 2), control input voltage (1.37 VDC), output type (AC/DC), mounting type (Surface Mount), and termination style (Gull Wing). Both are members of the COTOMOS™ series.

Performance Superiority: The C347S provides enhanced electrical performance across all load specifications. Load voltage range increases from 0–60 V to 0–80 V. Load current capacity increases from 360 mA to 1 A. On-state resistance decreases from 1.6 Ohms to 150 mOhms. These improvements ensure the substitute operates within or exceeds the original design envelope.

Compliance Alignment: Both components maintain ROHS3 compliance, Moisture Sensitivity Level 2 (1 Year), and REACH Unaffected status, ensuring regulatory and environmental requirements are met.

Product Availability: The C347S holds Active product status with 2206 units in stock, whereas the CS337 is Obsolete. This availability difference makes the C347S the practical choice for ongoing component procurement.

Package Consideration: The C347S uses an 8-SOP package (0.173", 4.40mm Width) compared to the CS337's 8-SMD package (0.300", 7.62mm). PCB layout modification is required to accommodate the different footprint.

Frequently Asked Questions (FAQ)

Q: Can the C347S directly replace the CS337 without PCB modification?

A: No. The C347S uses an 8-SOP package with 0.173" width, while the CS337 uses an 8-SMD package with 0.300" width. PCB layout changes are required to accommodate the different footprint and pin spacing.

Q: Are the electrical specifications of the C347S compatible with CS337 circuit designs?

A: Yes. The C347S maintains identical control input voltage (1.37 VDC), circuit configuration (SPST-NO 1 Form A x 2), and output type (AC/DC). The C347S provides superior load voltage range (0–80 V vs. 0–60 V), load current capacity (1 A vs. 360 mA), and lower on-state resistance (150 mOhms vs. 1.6 Ohms), making it suitable for applications designed for the CS337.

Q: What is the significance of the different package types?

A: The 8-SMD package is a larger Surface Mount Device package, while the 8-SOP is a smaller Small Outline Package. The dimensional difference affects PCB layout, component density, and assembly processes. Designs must be updated to accommodate the C347S footprint.

Q: Are both components RoHS3 compliant?

A: Yes. Both the CS337 and C347S are ROHS3 compliant with identical Moisture Sensitivity Level 2 (1 Year) ratings and REACH Unaffected status.

Q: Why is the CS337 listed as Obsolete?

A: The CS337 has reached end-of-life status and is no longer manufactured by Coto Technology. The C347S represents the current active product offering with equivalent or superior specifications.

Q: Can the C347S handle higher loads than the CS337?

A: Yes. The C347S is rated for 1 A load current compared to the CS337's 360 mA, and supports load voltages up to 80 V compared to 60 V. The C347S also features significantly lower on-state resistance (150 mOhms vs. 1.6 Ohms), resulting in reduced power dissipation and improved efficiency.

Q: What inventory status should be considered when selecting between these parts?

A: The CS337 has 794 units in stock but is obsolete and will not be replenished. The C347S has 2206 units in stock and is an active product with ongoing availability. For new designs and long-term support, the C347S is the recommended choice.