Pulse Electronics H1081 LAN Transformer - Equivalent & Substitute Parts

Part Overview

The Pulse Electronics H1081 is a LAN 10/100 Base-T pulse transformer designed for Ethernet data interface applications. It features a 1:1.41 transmitter and 1:1 receiver turns ratio configuration in a surface mount package. The H1081 is classified as obsolete, making identification of suitable substitute components essential for ongoing system support and new design implementations.

Substiute Parts

H1081

Pulse ElectronicsIn Stock: 1345H1081 Datasheet

Current PartRFQ

H1081NL

Pulse ElectronicsIn Stock: 1296H1081NL Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the H1081 is determined by the following critical parameters:

• Turns Ratio Configuration: Primary:Secondary ratio of 1:1.41 (transmitter) and 1:1 (receiver) must be maintained or functionally equivalent
• Mounting Type: Surface mount package required for PCB compatibility
• Physical Dimensions: Package footprint of 1.000" L x 0.395" W and maximum seated height of 0.230" must be preserved
• Operating Temperature Range: Minimum 0°C to 70°C operating window
• Transformer Application: LAN 10/100 Base-T or equivalent data interface isolation transformer

The H1081NL qualifies as a direct substitute based on matching all critical electrical and mechanical parameters while offering improved product status and compliance characteristics.

Parameter Comparison

Engineering Selection Recommendations

The H1081NL is the designated substitute for the obsolete H1081 component. Selection of the H1081NL is supported by the following factors:

• Product Status: The H1081NL maintains active product status, ensuring continued availability and manufacturer support
• Compliance: The H1081NL achieves ROHS3 compliance, addressing regulatory requirements that the original H1081 does not meet
• Electrical Compatibility: Turns ratio specifications are functionally equivalent (1:1.41 vs. 1:1.141 transmitter configuration)
• Mechanical Compatibility: Identical physical dimensions and mounting type ensure direct PCB footprint compatibility
• Moisture Sensitivity: Improved MSL rating (3 vs. 4) provides enhanced handling and storage flexibility
• Thermal Range: Operating temperature specification remains consistent across both components

Frequently Asked Questions (FAQ)

Q: Can the H1081NL be used as a direct replacement for the H1081 in existing designs?

A: Yes. The H1081NL maintains identical physical dimensions, mounting type, and functionally equivalent electrical specifications. PCB layout and component placement require no modification.

Q: What is the difference between the H1081 and H1081NL transformer types?

A: The H1081 is specified as a LAN 10/100 Base-T transformer, while the H1081NL is classified as an Isolation and Data Interface (Encapsulated) transformer. Both are designed for equivalent LAN data interface applications with matching turns ratios and operating characteristics.

Q: Are there compliance differences between these components?

A: Yes. The H1081NL is ROHS3 compliant, while the H1081 is RoHS non-compliant. For new designs or applications subject to RoHS regulations, the H1081NL is the required selection.

Q: What is the significance of the MSL rating difference?

A: The H1081 has MSL 4 (72-hour moisture sensitivity window), while the H1081NL has MSL 3 (168-hour window). The H1081NL provides a longer safe handling and storage period before reflow soldering, reducing moisture-related defect risk.

Q: Are the turns ratios identical between H1081 and H1081NL?

A: The turns ratios are functionally equivalent. The H1081 specifies 1:1.41 transmitter and 1:1 receiver, while the H1081NL specifies 1:1.141 transmitter and 1:1 receiver. This minor variation (1.41 vs. 1.141) is within acceptable tolerance for LAN transformer applications.

Q: What packaging is available for the H1081NL?

A: The H1081NL is supplied in tube packaging, suitable for automated assembly processes and component handling.