KSZ8081MNXIA-TR - 10/100 Ethernet PHY | Microchip
MPN: KSZ8081MNXIA-TR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.9311 | $0.93 |
| 10 | $0.9311 | $9.31 |
| 100 | $0.9311 | $93.11 |
| 500 | $0.9311 | $465.55 |
| 1,000 | $0.9311 | $931.10 |
KSZ8081MNXIA-TR Overview
What is an Ethernet PHY? An Ethernet physical-layer transceiver converts digital data from a network controller into electrical signaling for twisted-pair cabling and converts received cable signals back into digital data. A 10Base-T/100Base-TX PHY supports 10 Mbps and 100 Mbps Ethernet operation over CAT-5 UTP, while the host interface connects the PHY to a network controller or embedded processor. In the hierarchy of semiconductor components, the KSZ8081 is an Ethernet interface IC, then a network physical-layer transceiver, then a communication semiconductor.
The verified product information specifies a 32-QFN 5 x 5 mm package and single-supply operation. The KSZ8081 family is designed for compact Ethernet equipment, embedded systems, industrial controllers, communications equipment, and network interface designs. Its 10/100 capability provides compatibility with legacy 10 Mbps networks as well as Fast Ethernet links. The Full MII designation in the verified DigiKey listing identifies the host-side interface category; detailed pin functions, voltage ranges, temperature limits, and timing parameters must be taken from the manufacturer datasheet.
The KSZ8081MNXIA-TR is intended for designs using Ethernet magnetics and an RJ45 connector. The verified manufacturer product page describes support for transmission and reception over standard CAT-5 UTP. Hardware design must preserve the differential TX and RX pairs, provide the required decoupling, and follow the KSZ8081 hardware design guidance. Microchip's published KSZ8081 hardware design checklist notes that pin 2 of the RJ45 is RX- and should route through the magnetics to RXM pin 4 of the KSZ8081MNX when using the specified arrangement.
A key design consideration is that Ethernet PHY operation depends on a clean 3.3 V supply, correct magnetics, controlled impedance, and compliant physical-layer layout. Use the manufacturer datasheet and hardware design checklist for the authoritative pinout, exposed-pad connection, capacitor values, supported media, and interface timing. Do not infer undocumented electrical values from distributor descriptions.
This page combines verified distributor identity and package information with manufacturer-level application context and practical Ethernet layout guidance for engineers evaluating the KSZ8081MNXIA-TR.
Drop-in alternatives for KSZ8081MNXIA-TR — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with KSZ8081MNXIA-TR (same form factor and footprint) — differing in Cable Type, Package.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
KSZ8081MNXIA
✅ Drop-In📋 Reference alternative (not in catalog)
KSZ8081RNDIA-TR
✅ Drop-In📋 Reference alternative (not in catalog)
KSZ8081RNACA-TR
✅ Drop-In✓ In Stock
$0.77 / Unit
View Datasheet →KSZ8091MNXIA-TR
✅ Drop-In📋 Reference alternative (not in catalog)
KSZ8091RNBIA-TR
✅ Drop-In📋 Reference alternative (not in catalog)
KSZ8081MNXIA-TR Specifications
| Device Type | 10Base-T/100Base-TX Ethernet physical-layer transceiver |
| Supported Ethernet Speeds | 10 Mbps and 100 Mbps |
| Cable Type | CAT-5 unshielded twisted pair (UTP) |
| Host Interface | Full MII |
| Transceiver Configuration | 1/1 transceiver |
| Supply Type | Single supply |
| Package | 32-QFN, 5 x 5 mm |
| Mounting Type | Surface mount |
| Manufacturer | Microchip Technology |
| Function | Ethernet transmission and reception |
| Typical Network Use | 10/100 Ethernet copper network interface |
| Maximum Data Rate | 100 Mbps |
| Pin Count | 32 pins |
KSZ8081MNXIA-TR 32-qfn, 5 x 5 mm Pin Configuration Guide
Pin configuration for KSZ8081MNXIA-TR (32-qfn, 5 x 5 mm package). Pin numbering, functions, and connection diagrams are defined in the manufacturer datasheet. Refer to it for the exact footprint and soldering guidelines.
No detailed pinout data available for KSZ8081MNXIA-TR.
Refer to the datasheet for full pin configuration.
Typical Applications
KSZ8081MNXIA-TR is suitable for 6 applications: Embedded Ethernet Controller Interface, Industrial Control Gateway, Home and Building Network Equipment, Network Measurement and Test Equipment, Communications and Remote Monitoring, Compact Network Interface Module.
Embedded Ethernet Controller Interface
The KSZ8081MNXIA-TR fits an embedded product that needs a dedicated 10/100 copper Ethernet front end. Its verified Full MII identity provides a defined host-side interface to a network controller or microcontroller with an MII controller, while the PHY handles signaling across CAT-5 UTP. The 32-QFN 5 x 5 mm package helps reduce board area in compact gateways, controllers, and data-acquisition equipment. Before layout release, verify the MII timing, supply voltage, pin mapping, and exposed-pad connection against the manufacturer datasheet.
Recommended
Industrial Control Gateway
KSZ8081MNXIA-TR can be evaluated for an industrial gateway that bridges a local controller to a 10/100 Ethernet network. Its dual-rate support covers 10 Mbps and 100 Mbps links, and the CAT-5 UTP interface aligns with common industrial copper cabling. The compact 32-QFN 5 x 5 mm package is useful where board area is constrained. Industrial deployment still requires confirmation of operating temperature, EMC behavior, isolation strategy, and reliability requirements; those values are not present in the supplied snippets.
Recommended
Home and Building Network Equipment
The KSZ8081MNXIA-TR is applicable to access equipment, building controllers, and compact network appliances that connect to 10/100 Ethernet over twisted pair. A 100 Mbps-capable PHY supports practical throughput for control, status, telemetry, and management traffic while retaining compatibility with 10 Mbps links. The design must include suitable Ethernet magnetics, an RJ45 or equivalent connector, controlled-impedance routing, and the manufacturer's recommended power and decoupling arrangement. Verify environmental and compliance requirements before consumer deployment.
Recommended
Network Measurement and Test Equipment
KSZ8081MNXIA-TR can serve as the copper Ethernet interface in measurement instruments and test systems that need a compact 10/100 connection. The Full MII host interface can connect to a control FPGA or processor responsible for packet handling, while the PHY provides the physical layer over CAT-5 UTP. The 32-QFN 5 x 5 mm package supports dense front-panel or multi-channel equipment. Designers should isolate sensitive analog sections, verify return-path grounding, and validate cable immunity in the final enclosure.
Recommended
Communications and Remote Monitoring
The KSZ8081MNXIA-TR is suitable for remote monitoring equipment that periodically exchanges data over an existing copper Ethernet infrastructure. Supporting both 10Base-T and 100Base-TX allows the product to interoperate with older and newer network infrastructure, while the small QFN package helps meet compact enclosure requirements. The PHY must be paired with magnetics whose pinout matches the PCB routing, and the host controller must handle the Full MII interface and network stack. Confirm link reliability, temperature range, and compliance before field installation.
Recommended
Compact Network Interface Module
KSZ8081MNXIA-TR can form the Ethernet front end of a compact interface module or embedded communications daughtercard. Its 32-QFN 5 x 5 mm package provides a small PHY footprint, while the 10/100 capability supports standard copper Ethernet links without requiring a gigabit PHY. The module designer must provide the host MII signals, supply rails, magnetics, connector, and firmware or network-controller support. The verified data confirms the package and function but does not establish all timing, current, or environmental limits, so those values must be sourced from the manufacturer datasheet.
Recommended
Recommended Products Summary
Engineering reference data for KSZ8081MNXIA-TR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | KSZ8081MNXIA | KSZ8081RNDIA-TR | KSZ8081RNACA-TR | KSZ8091MNXIA-TR | KSZ8091RNBIA-TR |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Ethernet Function | 10Base-T/100Base-TX PHY | 10/100 Ethernet PHY | 10/100 Ethernet PHY | 10/100 Ethernet PHY | Related 10/100 Ethernet PHY candidate | Related 10/100 Ethernet PHY candidate |
Key Differentiators
- Verified Full MII host-interface identity (vs KSZ8081RNACA-TR)
- Confirmed 32-QFN 5 x 5 mm package identity (vs KSZ8091MNXIA-TR)
- 10Base-T and 100Base-TX support (vs KSZ8081RNBIA-TR)
- Documented Microchip hardware-design guidance (vs KSZ8081RNDIA-TR)
Design Notes
Route the Ethernet differential pairs as controlled-impedance traces and keep the TX and RX paths away from noisy switching nodes and high-current return paths. Follow the manufacturer KSZ8081 hardware design checklist and package-specific land pattern. The verified checklist specifically notes that RJ45 pin 2 is RX- and should route through the magnetics to RXM pin 4 for the specified KSZ8081MNX arrangement; confirm the final connector and magnetics pinout before fabrication.
Use the datasheet-recommended power and decoupling arrangement for the single-supply PHY, with short ground connections and a carefully planned exposed-pad treatment. The verified snippets do not state the input voltage range, capacitor values, or thermal resistance, so those values must be taken directly from Microchip documentation. Do not infer the exposed-pad connection from the package size alone because incorrect grounding can affect signal integrity and thermal performance.
Do not select a substitute based only on the shared 10/100 Ethernet function or the related KSZ8081 family name. A true replacement must match the package footprint, Full MII pin mapping, magnetics interface, supply limits, timing, temperature range, and exposed-pad requirements. The supplied cross-reference results identify related MPNs but do not provide enough verified data to confirm complete drop-in equivalence.
Validate the complete Ethernet channel with the selected magnetics and connector, including differential impedance, insertion loss, return loss, isolation, and crosstalk. The PHY's 100 Mbps capability does not guarantee link performance if the board layout or magnetics are unsuitable. Use manufacturer reference layouts and hardware design guidance, then verify the final design with Ethernet channel and EMC testing appropriate to the product enclosure.
Compliance Information
The supplied verified snippets do not provide exact RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals declarations for KSZ8081MNXIA-TR. Confirm current compliance information on the official Microchip product page or manufacturer documentation.
