JP026821UNL 10/100 Base-TX RJ45 MagJack for Ethernet Networks

ElecSuppliers Part Number GuideAug 28, 2026

JP026821UNL is a Pulse Electronics PULSEJACK™ 1-port RJ45 connector with integrated Ethernet magnetics, designed for 10/100 Base-TX Fast Ethernet applications. It combines the external RJ45 interface and magnetic components required by the Ethernet connection in a single PCB-mounted assembly.

That combination is the main reason this model appears in Ethernet-enabled electronic equipment. It is not simply a mechanical RJ45 socket. The integrated magnetic interface is part of the network connection between the Ethernet PHY and the external twisted-pair cable.

JP026821UNL Is Designed for 10/100 Base-TX Ethernet

The most important characteristic of JP026821UNL is its intended network speed.

It is specified for 10/100 Base-TX, making it suitable for Fast Ethernet interfaces rather than Gigabit Ethernet applications. The product documentation identifies it as a 100 Base-TX RJ45 1x1 connector with integrated magnetics.

This distinction is important when selecting a replacement. An RJ45 connector can look almost identical across different Ethernet generations, but the integrated transformer and electrical characteristics may be completely different.

If a design only requires 10 Mbps or 100 Mbps Ethernet, JP026821UNL provides the appropriate interface architecture.

The MagJack Integrates More Than the RJ45 Socket

The MagJack concept is central to understanding JP026821UNL.

An Ethernet interface normally requires magnetics between the PHY circuitry and the external network cable. With an integrated MagJack, those magnetic components are incorporated into the connector assembly rather than being placed as a completely separate transformer component on the PCB.

This can simplify the Ethernet section of a board and make the physical network interface more compact.

For engineers maintaining an existing PCB, this also means that replacing JP026821UNL with an ordinary RJ45 jack is not an equivalent substitution.

One Port for Embedded Ethernet Equipment

JP026821UNL is a single-port, single-row RJ45 design with through-hole mounting. It uses a right-angle orientation and solder termination.

The right-angle configuration is particularly practical for equipment where the Ethernet cable needs to exit through the side or rear panel.

This type of connector can be found in designs such as:

Industrial controllers

Embedded network equipment

ADSL-related equipment

LAN-on-Motherboard designs

Ethernet hubs and switches

Instrumentation and control hardware

The Pulse Electronics documentation specifically identifies ADSL modems, LAN-on-Motherboard systems, hubs and switches among the intended application categories.

Integrated LEDs Make Network Status Easier to See

JP026821UNL includes green and orange-yellow LED indicators.

For an Ethernet port, these LEDs provide a convenient visual interface for network status.

Instead of requiring a diagnostic tool to determine whether the port has established a connection, the equipment can provide basic link or activity information directly through the RJ45 opening.

The LED arrangement is also part of the exact component configuration, so it should be checked when selecting a substitute.

EMI Shielding Is Built Into the Connector

JP026821UNL is a shielded design with an EMI finger.

This is particularly relevant for an Ethernet connector because the RJ45 port creates a direct physical connection between the PCB and an external cable.

The cable and connector can become part of the equipment's electromagnetic environment.

The shielding structure can therefore contribute to the overall EMI strategy of the product.

It should not, however, be treated as a replacement for good PCB grounding, chassis design and Ethernet signal-layout practices.

The 13.97 mm Height Matters in Enclosure Design

The connector has a specified height above the PCB of approximately 13.97 mm.

For a new design, this dimension affects the position of the RJ45 opening in the enclosure.

For a replacement project, it can be even more important.

A substitute connector may have the same RJ45 interface but a different body height or mounting geometry. That can cause the connector to sit too high or too low relative to the equipment's panel opening.

This is one reason exact MPN matching is valuable for existing Ethernet hardware.

8-Position RJ45 Interface

The JP026821UNL is an 8-position RJ45 connector with gold-plated contacts. The contact material is phosphor bronze, while the housing uses thermoplastic material with a UL 94 V-0 flammability rating.

These details matter when comparing replacement parts.

An alternative RJ45 connector may have the same eight-position interface but use a different magnetic configuration, contact finish, shield design or mechanical arrangement.

The eight contacts alone are therefore not enough to establish compatibility.

Designed Around CAT 5 and CAT 6 Cabling

The product documentation indicates suitability for CAT 5 and CAT 6 UTP cable or better.

This makes JP026821UNL relevant to conventional twisted-pair Ethernet installations.

However, cable category and Ethernet speed should not be confused.

A CAT 6 cable may support much higher network performance in an appropriate system, but JP026821UNL itself is designed around the electrical characteristics of its specified 10/100 Base-TX interface.

The connector should therefore be selected according to the complete network architecture rather than the cable category alone.

What the Five Cores Tell Engineers

JP026821UNL is specified with five cores per jack.

This is another indication that the component is an integrated magnetic Ethernet connector rather than a simple mechanical RJ45 socket.

The internal magnetic structure is part of the component's electrical function.

For this reason, the pinout and transformer characteristics should be checked before using a different MagJack as a replacement.

Through-Hole Construction Suits Robust PCB Assembly

JP026821UNL uses through-hole mounting and solder termination.

An RJ45 connector can experience significant mechanical force every time a network cable is inserted or removed.

Through-hole mounting provides mechanical anchoring through the PCB in addition to the soldered electrical connection.

For equipment where the Ethernet cable is frequently connected and disconnected, this mechanical characteristic can be important.

The Operating Temperature Is 0°C to 70°C

The specified operating temperature range is 0°C to 70°C.

This should be considered carefully when evaluating JP026821UNL for industrial environments.

A visually similar MagJack intended for an extended industrial temperature range may have a different specification and should not automatically be considered equivalent.

The temperature requirement of the finished equipment should be compared with the exact component specification.

JP026821UNL Has Reached End of Life

An important sourcing consideration is that major distributor listings currently identify JP026821UNL as obsolete or scheduled for discontinuation. DigiKey lists it as obsolete, while Mouser identifies it as end-of-life and scheduled for discontinuation.

This changes the procurement strategy.

For an existing product that already uses JP026821UNL, locating remaining genuine stock may be preferable to redesigning the Ethernet interface.

For a new product, engineers should consider whether a current-production replacement can provide the same footprint, pinout, magnetic characteristics and mechanical configuration.

Replacing JP026821UNL Is Not Just an RJ45 Substitution

A replacement needs to match several characteristics simultaneously.

The most important checks include:

10/100 Base-TX operation

Integrated magnetics

1x1 port configuration

8-position RJ45 interface

Right-angle orientation

Through-hole mounting

LED configuration

EMI shielding

Pin assignment

Mechanical dimensions

Operating temperature

A replacement that matches only the RJ45 appearance is not sufficient.

The magnetic interface is particularly important because it directly affects the Ethernet signal path.

Why Engineers May Still Search for JP026821UNL

Although JP026821UNL is no longer a preferred choice for a new design, the exact part number remains important for maintenance and production support.

Existing equipment may have been designed around its footprint and magnetic characteristics.

In that situation, an engineer is not necessarily looking for the newest Ethernet connector.

They may simply need the same JP026821UNL to repair an existing board without changing the PCB.

That makes exact-part-number sourcing particularly valuable.

Finding the Exact JP026821UNL

For buyers searching this model, JP026821UNL should be used as the primary search term, while the manufacturer should be identified as Pulse Electronics.

The product's combination of 10/100 Base-TX support, integrated magnetics, LED indicators, EMI shielding and right-angle through-hole construction gives the model a very specific role in Ethernet hardware.

For supplier discovery, ElecSuppliers can provide another channel for buyers looking specifically for JP026821UNL and checking available sourcing options.

The key point is that JP026821UNL is best understood as a 10/100 Base-TX integrated Ethernet MagJack, not simply as an RJ45 connector. Its exact magnetic configuration and mechanical interface are what make the part relevant to existing Ethernet designs.