PRMA1C05B Reed Relay SPDT 250mA 5V Equivalent & Substitute Parts

Part Overview

The PRMA1C05B is a through-hole mounted reed relay manufactured by Coto Technology, configured as a single-pole double-throw (SPDT) switch with a 5VDC coil and 250mA contact rating. This component operates with a non-latching coil type and includes an integrated diode for transient suppression. The PRMA1C05B carries an obsolete product status, making identification of functionally equivalent alternatives necessary for ongoing design support, maintenance, and production continuity.

Substiute Parts

PRMA1C05B

Coto TechnologyIn Stock: 1151PRMA1C05B Datasheet

Current PartRFQ

HE721C0510

Littelfuse Inc.In Stock: 1279HE721C0510 Datasheet

DirectRFQ

DIP05-1C90-51D

Standex-Meder ElectronicsIn Stock: 888DIP05-1C90-51D Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the PRMA1C05B is determined by strict equivalence across the following critical parameters:

Core Electrical Requirements:

• Coil voltage: 5VDC (exact match required)
• Contact form: SPDT (1 Form C) configuration
• Contact current rating: 250 mA minimum
• Coil current: 25 mA (standard for this class)
• Coil type: Non-latching operation
• Integrated diode feature

Mechanical & Interface Requirements:

• Mounting type: Through-hole configuration
• Termination style: PC pin connection
• Coil resistance: 200 Ohms

Regulatory & Environmental Requirements:

• RoHS compliance (RoHS3 acceptable for active parts)
• REACH unaffected status
• Moisture sensitivity level: 1 (Unlimited)

The substitute parts HE721C0510 (Littelfuse Inc., HE700 series) and DIP05-1C90-51D (Standex-Meder Electronics, DIP series) satisfy all core electrical, mechanical, and regulatory criteria. Both parts maintain active product status, ensuring long-term availability and supply chain stability compared to the obsolete PRMA1C05B.

Parameter Comparison

Engineering Selection Recommendations

HE721C0510 (Littelfuse Inc., HE700 Series)

The HE721C0510 is a direct functional equivalent with active product status and ROHS3 compliance. This part maintains identical coil voltage, contact configuration, current ratings, and coil resistance to the PRMA1C05B. The HE721C0510 offers an extended upper operating temperature limit of 85°C compared to 80°C on the original part, and improved switching voltage capability at 175VDC maximum. The must-release voltage is lower at 0.5VDC, indicating slightly more sensitive release characteristics. This part is suitable for applications requiring long-term supply chain stability and modern compliance certifications.

DIP05-1C90-51D (Standex-Meder Electronics, DIP Series)

The DIP05-1C90-51D is a functionally equivalent alternative with active product status and ROHS3 compliance. This part matches all core electrical specifications including coil voltage, contact form, current ratings, and coil resistance. The DIP05-1C90-51D demonstrates faster switching performance with operate time of 0.7ms and release time of 1.5ms, compared to 2ms and 3ms respectively on the PRMA1C05B. The operating temperature range is narrower at -20°C to 70°C. This part is appropriate for applications where faster switching response is beneficial and operating conditions remain within the specified temperature envelope.

Both substitute parts carry active product status, ensuring availability for new designs and ongoing production requirements. Selection between HE721C0510 and DIP05-1C90-51D depends on specific application requirements regarding switching speed, temperature range, and supply chain preferences.

Frequently Asked Questions (FAQ)

Q: Can the HE721C0510 or DIP05-1C90-51D be used as direct replacements for the PRMA1C05B in existing designs?

A: Both parts satisfy the core electrical and mechanical requirements for substitution. The PRMA1C05B, HE721C0510, and DIP05-1C90-51D share identical coil voltage (5VDC), contact form (SPDT), contact current rating (250mA), coil current (25mA), coil resistance (200 Ohms), and through-hole PC pin termination. Direct PCB-level substitution is supported from an electrical and mechanical interface perspective. Application-specific validation is required for timing-critical circuits due to differences in operate and release times.

Q: What are the key differences in switching performance between these parts?

A: The PRMA1C05B specifies 2ms operate time and 3ms release time. The HE721C0510 operates at 3ms and releases at 3ms. The DIP05-1C90-51D demonstrates faster switching with 0.7ms operate time and 1.5ms release time. Applications with strict timing requirements must account for these variations.

Q: Are there temperature range limitations when substituting these parts?

A: The PRMA1C05B operates from -40°C to 80°C. The HE721C0510 extends the upper limit to 85°C. The DIP05-1C90-51D operates from -20°C to 70°C, which is narrower at both extremes. Applications requiring full -40°C operation should use the PRMA1C05B or HE721C0510. Applications limited to -20°C minimum may use the DIP05-1C90-51D.

Q: Do all three parts meet current regulatory requirements?

A: The PRMA1C05B carries RoHS Compliant status. The HE721C0510 and DIP05-1C90-51D both carry ROHS3 Compliant status, representing the current RoHS directive iteration. All three parts maintain REACH Unaffected status. Both substitute parts meet modern regulatory compliance requirements.

Q: What is the significance of the must-operate and must-release voltage specifications?

A: Must-operate voltage is the minimum coil voltage at which the relay is guaranteed to close its contacts. Must-release voltage is the maximum coil voltage at which the relay is guaranteed to open its contacts. The PRMA1C05B requires 3.75VDC to operate and releases below 0.8VDC. The HE721C0510 matches the operate voltage at 3.75VDC but releases at 0.5VDC, indicating faster release response. The DIP05-1C90-51D operates at 3.5VDC and releases at 0.75VDC. These differences affect circuit timing and control signal requirements.

Q: Are the packaging formats compatible?

A: All three parts use through-hole PC pin termination suitable for standard PCB mounting. The PRMA1C05B packaging is listed as dash (standard through-hole). The HE721C0510 and DIP05-1C90-51D are supplied in tube packaging. Tube packaging does not affect PCB compatibility; it reflects supply and handling format only.

Q: What is the moisture sensitivity level, and why is it relevant?

A: All three parts carry Moisture Sensitivity Level 1 (Unlimited), indicating no moisture sensitivity restrictions. These components do not require special moisture control during storage, handling, or assembly, simplifying logistics and manufacturing processes.