LAN8742A-CZ-TR Ethernet PHY for Compact Network Designs

ElecSuppliers Part Number GuideSep 06, 2026

LAN8742A-CZ-TR is a Microchip 10/100 Ethernet physical layer transceiver designed to connect an embedded system's Ethernet MAC to a standard twisted-pair network. It supports 10BASE-T and 100BASE-TX operation and provides both MII and RMII host interfaces.

The device combines Ethernet physical-layer functions with power-management features, cable diagnostics and automatic interface configuration in a compact 24-pin SQFN package. Its small footprint makes it suitable for embedded products where Ethernet connectivity needs to be integrated without occupying excessive PCB area.

10/100Mbps Ethernet Operation

LAN8742A-CZ-TR supports Ethernet data rates of 10Mbps and 100Mbps. The integrated PHY handles the analog and digital functions required to transmit and receive Ethernet data through the external magnetics and twisted-pair interface.

Auto-negotiation allows the PHY to establish the appropriate speed and duplex configuration with the connected Ethernet equipment. The device also supports full-duplex operation and incorporates automatic polarity correction to simplify network interface implementation.

For embedded systems that do not require Gigabit Ethernet, a 10/100Mbps PHY such as LAN8742A-CZ-TR provides a compact solution for conventional Fast Ethernet connectivity.

MII and RMII Host Interfaces

One of the useful characteristics of LAN8742A-CZ-TR is its support for both MII and RMII interfaces. MII provides a conventional connection between an Ethernet MAC and PHY, while RMII reduces the number of interface signals required by the host processor.

RMII is particularly useful in microcontroller-based designs where available I/O pins and PCB routing resources are limited. The interface can provide the required Ethernet connection while using fewer signals than a traditional MII implementation.

This flexibility allows LAN8742A-CZ-TR to be considered for a wide range of embedded processors and microcontrollers with integrated Ethernet MAC functionality.

flexPWR Technology

LAN8742A-CZ-TR incorporates Microchip's flexPWR technology for flexible power operation. The device supports a supply range suitable for low-voltage embedded systems and provides an integrated 1.2V regulator for the PHY core.

The I/O supply architecture allows the device to interface with different host logic voltage levels, helping simplify connections to processors operating at lower digital supply voltages.

Integrated power-management functions also allow the Ethernet interface to enter reduced-power operating modes when full network activity is not required.

HP Auto-MDIX

LAN8742A-CZ-TR integrates HP Auto-MDIX, allowing the PHY to automatically determine the appropriate transmit and receive pair configuration.

This eliminates the need for the system designer to depend on a specific straight-through or crossover cable configuration. For embedded networking equipment, this can simplify installation and reduce the amount of software or hardware configuration needed to establish an Ethernet link.

The device also provides cable diagnostic functionality that can assist with identifying physical-layer connection problems during development and maintenance.

Compact 24-Pin SQFN Package

LAN8742A-CZ-TR is housed in a 24-pin SQFN package with an approximately 4 mm × 4 mm footprint. The compact package integrates the Ethernet PHY and supporting functions while keeping the PCB area requirement low.

The exposed-pad package also provides an effective thermal and electrical connection to the PCB when the recommended land pattern and grounding arrangement are followed.

For small embedded boards, the compact package can be useful when the Ethernet interface must coexist with processors, memory, wireless modules, power converters and other high-density circuitry.

Power Saving and Wake-Up Functions

LAN8742A-CZ-TR provides low-power operating modes for systems that need to reduce Ethernet-related power consumption. Wake-on-LAN functionality can also be incorporated into system power-management strategies where the network interface needs to remain capable of detecting specific network activity.

These functions can be useful in embedded equipment that spends extended periods in standby but still needs to respond to network commands or remote wake-up events.

Commercial Temperature Version

The LAN8742A-CZ-TR ordering code represents the standard commercial-temperature version of the LAN8742A family. The Microchip device identification system specifies the LAN8742A-CZ-TR for operation from 0°C to +70°C, while the industrial-temperature LAN8742Ai version uses the “i” designation.

The “TR” suffix identifies the tape-and-reel packaging option. This distinction is important when selecting the exact device for automated PCB assembly, because LAN8742A-CZ and LAN8742A-CZ-TR use different packaging formats while sharing the same basic PHY function.

Applications for LAN8742A-CZ-TR

LAN8742A-CZ-TR can be used in embedded computers, networked industrial equipment, printers, test instruments, consumer electronics, digital video equipment and other products requiring 10/100Mbps Ethernet connectivity.

Its combination of MII/RMII support, HP Auto-MDIX, flexible power operation and compact packaging makes it suitable for processor-based designs where Ethernet connectivity needs to fit within a limited PCB area.

When selecting between LAN8742A-CZ-TR and the industrial LAN8742Ai-CZ-TR variant, designers should pay particular attention to the specified operating-temperature range as well as the required packaging format. This helps ensure that the selected ordering code matches both the environmental requirements and the intended manufacturing process.