CS474 Solid State Relay SPST-NC

Part Overview

The CS474 is a Solid State Relay (SSR) manufactured by Coto Technology, featuring SPST-NC (1 Form B) switching configuration with a rated load current capacity of 90 mA across 0–400 V AC/DC applications. This component is classified as Obsolete, necessitating identification of functionally equivalent alternatives from the active product portfolio. The COTOMOS™ series provides suitable substitutes that maintain electrical compatibility while offering continued availability and supply chain reliability.

Substiute Parts

CS474

Coto TechnologyIn Stock: 1145CS474 Datasheet

Current PartRFQ

C574S

Coto TechnologyIn Stock: 2973C574S Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the CS474 must maintain compatibility across the following critical electrical and mechanical parameters:

Electrical Compatibility Criteria:

• Circuit configuration: SPST-NC (1 Form B)
• Input voltage: 1.37 VDC
• Load voltage range: 0 V – 400 V
• Output type: AC, DC capable
• On-state resistance: 50 Ohms maximum

Mechanical and Regulatory Criteria:

• Mounting type: Surface Mount
• Termination style: Gull Wing
• RoHS3 compliance
• MSL rating: 2 (1 Year)
• Series: COTOMOS™

Load Current Consideration: The substitute part C574S operates at a rated load current of 70 mA, which represents a 22% reduction from the CS474's 90 mA rating. This substitution is valid only where the application load current does not exceed 70 mA.

Parameter Comparison

Engineering Selection Recommendations

The C574S serves as the primary substitute for the obsolete CS474, offering continued product availability within the COTOMOS™ series. Both parts maintain identical electrical specifications for input voltage (1.37 VDC), load voltage range (0–400 V), on-state resistance (50 Ohms max), and output type (AC/DC). Both comply with ROHS3 standards and share equivalent MSL ratings.

The principal design consideration involves load current capacity. The C574S is rated at 70 mA versus the CS474's 90 mA. Applications with maximum load currents not exceeding 70 mA experience no functional degradation. Applications requiring full 90 mA capacity at the specified load voltages must either source remaining CS474 inventory or conduct circuit redesign to reduce load current through alternative topologies.

The C574S package transitions from 6-SMD (0.300", 7.62mm) to 4-SOP (0.173", 4.40mm), reducing footprint area by approximately 41%. PCB layout and component placement must accommodate this dimensional change.

Frequently Asked Questions (FAQ)

Q: Can the C574S replace the CS474 in all applications?

A: The C574S is electrically compatible provided the application load current does not exceed 70 mA. If your circuit requires the full 90 mA capacity, alternative mitigation strategies must be evaluated.

Q: What is the impact of the package change from 6-SMD to 4-SOP?

A: The 4-SOP package reduces PCB footprint area and component height. PCB layout requires adjustment to accommodate the smaller form factor. Gull wing termination remains consistent, maintaining compatibility with standard reflow soldering processes.

Q: Are there regulatory or compliance concerns with substitution?

A: Both parts maintain ROHS3 compliance and identical MSL ratings. No regulatory barriers prevent substitution within the specified electrical operating window (≤70 mA load current).

Q: What is the inventory status of each part?

A: The CS474 (Obsolete) has 1,101 units available. The C574S (Active) has 2,892 units in stock, providing superior long-term supply chain continuity.

Q: Does the on-state resistance specification differ between parts?

A: Both parts specify 50 Ohms maximum on-state resistance, ensuring equivalent voltage drop characteristics at rated load currents within their respective current limits.