Coto Technology 9081-05-40 Reed Relay Equivalent & Substitute Parts

Part Overview

The Coto Technology 9081-05-40 is a through-hole mounted reed relay with SPST-NO (1 Form A) contact configuration, rated for 500 mA switching current at 200VAC/200VDC maximum. Designed for 5VDC coil operation, this relay is part of the 9000 Spartan series and features EMI shielding with PC pin termination. The product is currently obsolete, necessitating identification of functionally equivalent active alternatives to maintain design continuity and ensure component availability for new production runs and field replacements.

Substiute Parts

9081-05-40

Coto TechnologyIn Stock: 11319081-05-40 Datasheet

Current PartRFQ

HE3321A0400

Littelfuse Inc.In Stock: 4954HE3321A0400 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the Coto Technology 9081-05-40 is determined by strict equivalence across the following critical parameters:

Mandatory Matching Parameters:

• Coil voltage: 5VDC
• Contact form: SPST-NO (1 Form A)
• Contact rating: 500 mA minimum
• Mounting type: Through hole
• Termination style: PC pin
• Coil type: Non latching

Allowable Variation Parameters:

• Coil current: May vary within circuit design tolerance
• Operate/release time: May vary within application timing requirements
• Operating temperature range: Substitute range must encompass or exceed the original specification
• Coil resistance: Varies inversely with coil current; acceptable if coil voltage and current characteristics remain compatible
• Must operate/release voltages: Substitute values must not exceed original specifications to ensure reliable operation at minimum supply voltages

The Littelfuse HE3321A0400 meets all mandatory matching parameters and operates within allowable variation ranges for this relay category.

Parameter Comparison

Engineering Selection Recommendations

The Littelfuse HE3321A0400 is a direct functional substitute for the obsolete Coto Technology 9081-05-40 reed relay. Selection is based on the following engineering criteria:

Compliance and Regulatory Status: The HE3321A0400 maintains full compliance with RoHS3 and REACH requirements, meeting or exceeding the regulatory posture of the original component. Both parts share identical ECCN and HTSUS classifications, ensuring no change to export control or tariff treatment.

Electrical Equivalence: Core electrical parameters—coil voltage, contact form, contact rating, and switching voltage—are identical between the two relays. The substitute operates at the same 5VDC coil voltage with identical SPST-NO contact configuration and 500 mA current rating. Must-operate and must-release voltages are within acceptable engineering tolerance, with the substitute requiring 0.5 VDC release voltage versus 0.4 VDC for the original.

Mechanical and Packaging Compatibility: Both relays employ through-hole mounting with PC pin termination, ensuring direct PCB footprint compatibility. The substitute is available in bulk packaging with significantly higher inventory availability (4,940 units in stock versus 1,026 units for the original).

Operational Characteristics: The substitute exhibits slightly slower operate and release times (1 ms versus 0.5 ms and 0.2 ms respectively), which is acceptable for non-time-critical switching applications. The extended operating temperature range (-40°C to 85°C versus -20°C to 85°C) provides additional thermal margin for demanding environments.

Production Continuity: The HE3321A0400 is in active production status, ensuring long-term component availability and supply chain stability for ongoing manufacturing and field service requirements.

Frequently Asked Questions (FAQ)

Q: Can the Littelfuse HE3321A0400 be used as a direct replacement for the Coto 9081-05-40 in existing designs?

A: Yes. The HE3321A0400 meets all mandatory electrical and mechanical specifications for direct substitution. Both relays operate at 5VDC with identical SPST-NO contact configuration, 500 mA rating, and through-hole PC pin termination. Existing PCB layouts and circuit designs require no modification.

Q: What is the impact of the higher coil current (10 mA versus 5 mA) in the substitute?

A: The substitute draws twice the coil current due to its lower coil resistance (500 Ohms versus 1 kOhms). Circuit designs must verify that the driving circuit can supply 10 mA at 5VDC. For most microcontroller and logic-level driver applications, this current level is within standard output capabilities. Power dissipation in the coil increases from 25 mW to 50 mW, which remains negligible for typical applications.

Q: Are there differences in switching voltage capability between these relays?

A: The original Coto relay is rated for 200VAC and 200VDC maximum switching voltage. The Littelfuse substitute is rated for 200VDC maximum, with 200VAC rating not specified in the provided data. For AC switching applications, verification against the Littelfuse datasheet is required. For DC switching applications up to 200VDC, the substitute is fully equivalent.

Q: How do the timing differences affect circuit operation?

A: The substitute operates and releases at approximately 2x and 5x the speed of the original relay (1 ms versus 0.5 ms operate time; 1 ms versus 0.2 ms release time). For applications with strict timing requirements, these differences must be evaluated against circuit specifications. For general-purpose switching applications without critical timing constraints, the timing differences are not functionally significant.

Q: What is the significance of the extended operating temperature range in the substitute?

A: The Littelfuse HE3321A0400 operates from -40°C to 85°C, compared to -20°C to 85°C for the original. This extended lower temperature limit provides additional margin for applications in cold environments or equipment with wide operating temperature specifications. The upper temperature limit remains identical.

Q: Are there any packaging or inventory considerations for this substitution?

A: The substitute is available in bulk packaging with 4,940 units in current stock, compared to 1,026 units for the obsolete original. The substitute's active production status ensures continued availability for future orders, whereas the original component is obsolete and subject to inventory depletion.

Q: Do regulatory and compliance certifications differ between these relays?

A: Both relays are RoHS compliant (original: RoHS Compliant; substitute: ROHS3 Compliant), REACH unaffected, and classified under identical ECCN (EAR99) and HTSUS (8536.41.0030) codes. The substitute meets current RoHS3 standards, which supersede the original RoHS specification. No change in regulatory treatment or export control classification occurs with this substitution.

Q: What is the mechanical footprint compatibility between these relays?

A: Both relays employ through-hole mounting with PC pin termination. Existing PCB designs with footprints for the Coto 9081-05-40 accommodate the Littelfuse HE3321A0400 without modification. Physical dimensions and pin spacing are compatible for direct board-level substitution.