D3421 Telecom Relay DPDT 2A 3V Equivalent & Substitute Parts

Part Overview

The D3421 is a telecom-grade double-pole double-throw (DPDT) relay manufactured by TE Connectivity Potter & Brumfield Relays, designed for 3VDC coil operation with 2A contact rating. This component operates at 250VAC and 220VDC maximum switching voltages and features through-hole PC pin termination suitable for printed circuit board assembly.

The D3421 is classified as obsolete. Locating equivalent substitute parts is necessary to support ongoing maintenance, repair, and production requirements for legacy systems utilizing this relay specification.

Substiute Parts

D3421

TE Connectivity Potter & Brumfield RelaysIn Stock: 939D3421 Datasheet

Current PartRFQ

TX2-3V

Panasonic Electric WorksIn Stock: 3405TX2-3V Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the D3421 is determined by strict equivalence across the following critical parameters:

Mandatory Matching Parameters:

• Coil Voltage: 3VDC
• Contact Form: DPDT (2 Form C)
• Contact Rating (Current): 2 A
• Mounting Type: Through Hole
• Termination Style: PC Pin
• Coil Type: Non Latching
• Relay Type: Telecom

Operational Compatibility Parameters:

• Must Operate Voltage: 2.25 VDC minimum
• Must Release Voltage: 0.3 VDC maximum
• Operating Temperature Range: Must encompass or match the required application range

The TX2-3V from Panasonic Electric Works meets all mandatory matching parameters and operational compatibility requirements, qualifying it as a direct substitute for the D3421.

Parameter Comparison

Engineering Selection Recommendations

The TX2-3V from Panasonic Electric Works is the qualified substitute for the obsolete D3421. Selection of the TX2-3V is supported by the following factors:

Product Status: The TX2-3V maintains active production status, ensuring availability and supply chain continuity compared to the obsolete D3421.

Regulatory Compliance: Both components are RoHS compliant. The TX2-3V carries ROHS3 compliance certification, meeting current regulatory requirements. Both components are classified under ECCN EAR99 and share the same HTSUS code (8536.41.0020).

Functional Equivalence: The TX2-3V matches all critical electrical parameters required for direct substitution: 3VDC coil voltage, DPDT contact configuration, 2A contact rating, through-hole PC pin termination, and identical must-operate and must-release voltage thresholds.

Performance Characteristics: The TX2-3V exhibits faster switching response times (4 ms operate and release versus 5 ms for the D3421) and lower coil current draw (46.7 mA versus 66.7 mA), representing improved operational efficiency.

Temperature Consideration: The TX2-3V operating temperature range (-40°C ~ 85°C) is narrower at the lower bound compared to the D3421 (-55°C ~ 85°C). Applications requiring operation below -40°C require evaluation against specific system requirements.

Frequently Asked Questions (FAQ)

Q: Can the TX2-3V directly replace the D3421 in existing circuit designs?

A: Yes. The TX2-3V meets all mandatory electrical and mechanical parameters for direct substitution. Both components share identical coil voltage (3VDC), contact configuration (DPDT), current rating (2A), mounting type (through-hole), and termination style (PC pin). No circuit modifications are required.

Q: What is the difference in coil resistance between these relays?

A: The D3421 has 45 Ohms coil resistance while the TX2-3V has 64.3 Ohms. This difference results in lower coil current draw for the TX2-3V (46.7 mA versus 66.7 mA). Both relays meet the same must-operate voltage threshold (2.25 VDC), ensuring functional compatibility in the application circuit.

Q: Are there packaging differences between the D3421 and TX2-3V?

A: The D3421 is supplied with standard packaging notation (-), while the TX2-3V is packaged in tubes. Both components use identical through-hole PC pin termination. Tube packaging does not affect electrical performance or circuit board assembly compatibility.

Q: What is the switching voltage difference between these relays?

A: The D3421 supports 250VAC and 220VDC maximum switching voltages. The TX2-3V supports 220VDC maximum switching voltage. For applications requiring 250VAC switching capability, the D3421 specification must be verified against actual system requirements. For 220VDC or lower applications, the TX2-3V is fully compatible.

Q: How do the switching times compare?

A: The TX2-3V operates and releases faster than the D3421. The TX2-3V achieves 4 ms operate time and 4 ms release time, compared to 5 ms for both parameters on the D3421. This faster response may provide performance benefits in time-sensitive applications.

Q: Is the TX2-3V suitable for low-temperature applications?

A: The TX2-3V operates from -40°C to 85°C. The D3421 operates from -55°C to 85°C. Applications requiring operation below -40°C must use the D3421 or identify alternative components with extended low-temperature ratings. For applications within the -40°C to 85°C range, the TX2-3V is fully suitable.

Q: Are both relays RoHS compliant?

A: Yes. The D3421 is RoHS compliant. The TX2-3V is ROHS3 compliant, meeting current regulatory standards. Both components satisfy RoHS requirements for new designs and legacy system support.