RM05-4AS-4/2 Reed Relay Equivalent & Substitute Parts

Part Overview

The RM05-4AS-4/2 is a 4-pole single-throw (4PST) reed relay manufactured by Standex-Meder Electronics, designed for 5VDC coil operation with 300mA contact rating. This component is classified as obsolete, making identification of functionally equivalent substitute parts essential for ongoing system support and new design implementations.

Reed relays in this category serve applications requiring low-power switching control with fast response times and compact form factors. The obsolete status of the RM05-4AS-4/2 necessitates evaluation of active alternative components that maintain electrical and mechanical compatibility within system constraints.

Substiute Parts

RM05-4AS-4/2

Standex-Meder ElectronicsIn Stock: 860RM05-4AS-4/2 Datasheet

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CRF05-1A

Standex-Meder ElectronicsIn Stock: 1751CRF05-1A Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the RM05-4AS-4/2 is evaluated based on the following critical electrical and mechanical parameters:

Coil Parameters: Coil voltage (5VDC), coil current draw, and coil resistance determine drive circuit compatibility. Substitute parts must operate from the same 5VDC supply with comparable activation thresholds (Must Operate Voltage ≥ 3.75VDC).

Contact Parameters: Contact form configuration, current rating, and switching voltage establish load-switching capability. The RM05-4AS-4/2 provides four independent SPST-NO contacts rated for 300mA at 180VAC/180VDC maximum.

Timing Parameters: Operate and release times affect system response characteristics. Faster switching times in substitute parts do not preclude compatibility but may require circuit validation in timing-critical applications.

Environmental & Compliance: Operating temperature range, RoHS3 compliance, and REACH status ensure regulatory alignment and thermal performance within specified bounds.

Packaging & Mounting: Surface mount termination and BGA package style define PCB integration requirements.

The CRF05-1A represents a functionally related component from the same manufacturer with differing contact configuration and current rating, requiring application-specific evaluation.

Parameter Comparison

Engineering Selection Recommendations

For Direct Functional Replacement:

The CRF05-1A cannot serve as a direct pin-for-pin substitute for the RM05-4AS-4/2 due to fundamental architectural differences: the RM05-4AS-4/2 provides four independent SPST-NO contact sets, while the CRF05-1A provides a single contact set. Applications requiring four simultaneous switching channels cannot be satisfied by the CRF05-1A without circuit redesign.

For Single-Channel Applications:

In applications utilizing only one of the four contact channels in the RM05-4AS-4/2, the CRF05-1A presents an active alternative with the following considerations:

• Both components operate from 5VDC coil supply with identical activation threshold (3.75VDC Must Operate Voltage)
• CRF05-1A contact rating (500mA) exceeds RM05-4AS-4/2 (300mA), providing margin for higher-current loads
• CRF05-1A switching voltage rating (170VAC/170VDC) is 10V lower than RM05-4AS-4/2; applications switching loads above 170V require the RM05-4AS-4/2 or alternative components
• CRF05-1A exhibits significantly faster switching times (0.1ms operate vs. 0.6ms; 0.02ms release vs. 0.05ms), suitable for timing-sensitive circuits
• CRF05-1A Must Release Voltage (0.75VDC) exceeds RM05-4AS-4/2 (0.5VDC), affecting hold-time behavior in low-voltage control circuits
• CRF05-1A operating temperature range (-40°C ~ 125°C) exceeds RM05-4AS-4/2 (-20°C ~ 85°C), providing extended thermal capability
• Termination style differs (SMD Tab vs. BGA), requiring PCB layout modification

Compliance Status:

Both components maintain ROHS3 compliance and REACH unaffected status, satisfying regulatory requirements for new designs and legacy system support.

Availability:

CRF05-1A is actively produced (1700 Pcs in stock) versus RM05-4AS-4/2 obsolete status (795 Pcs remaining inventory), establishing CRF05-1A as the preferred long-term sourcing option where application parameters permit substitution.

Frequently Asked Questions (FAQ)

Q: Can the CRF05-1A replace the RM05-4AS-4/2 in all applications?

A: No. The RM05-4AS-4/2 provides four independent SPST-NO contact channels, while the CRF05-1A provides one. Direct replacement is only possible in applications using a single contact channel. Multi-channel applications require alternative solutions or circuit redesign.

Q: What is the primary electrical difference between these relays?

A: The RM05-4AS-4/2 is a 4PST (4-pole single-throw) relay with four contact sets, each rated 300mA at 180VAC/180VDC maximum. The CRF05-1A is a single-pole SPST-NO relay with one contact set rated 500mA at 170VAC/170VDC maximum. Both operate from 5VDC coil supply.

Q: Are the switching speed differences significant?

A: Yes. The CRF05-1A operates in 0.1ms and releases in 0.02ms, compared to the RM05-4AS-4/2 at 0.6ms operate and 0.05ms release. Applications with timing-critical switching requirements must account for these differences. Faster switching in the CRF05-1A may require circuit validation in systems designed around the RM05-4AS-4/2 timing characteristics.

Q: What is the impact of different termination styles?

A: The RM05-4AS-4/2 uses BGA termination while the CRF05-1A uses SMD (SMT) Tab termination. These require different PCB footprints and assembly processes. Substitution necessitates PCB redesign and re-qualification of assembly procedures.

Q: Can the CRF05-1A handle higher loads than the RM05-4AS-4/2?

A: The CRF05-1A contact rating (500mA) exceeds the RM05-4AS-4/2 (300mA), providing higher current capacity per contact. However, the CRF05-1A switching voltage maximum (170VAC/170VDC) is 10V lower than the RM05-4AS-4/2 (180VAC/180VDC). Load compatibility depends on both current and voltage requirements.

Q: What does the Must Release Voltage difference mean for circuit design?

A: The RM05-4AS-4/2 releases at 0.5VDC while the CRF05-1A releases at 0.75VDC. In circuits where coil voltage drops below the release threshold during operation, the CRF05-1A may release earlier. Control circuits must ensure adequate voltage margin above the release threshold for reliable operation.

Q: Are both components RoHS3 compliant?

A: Yes. Both the RM05-4AS-4/2 and CRF05-1A are ROHS3 compliant and REACH unaffected, meeting current environmental and regulatory requirements for electronic components.

Q: Which component should be selected for new designs?

A: For new single-channel switching applications, the CRF05-1A is the recommended choice due to active production status, wider operating temperature range (-40°C ~ 125°C vs. -20°C ~ 85°C), and higher contact current rating (500mA vs. 300mA). Applications requiring four simultaneous switching channels or switching voltages above 170V require alternative component evaluation.