Single-pair Ethernet PHY for space-constrained automotive applications

Microchip Technology has announced the LAN8770, an OPEN Alliance TC10 sleep standard Ethernet PHY with what is claimed the industry’s lowest sleep current – less than 15µA – which is around four times lower than other accessible devices.

The device is a cost-effective, compact, single-port 100BASE-T1 Ethernet PHY compliant with the IEEE 802.3bw-2015 specification and offered in a 5mm x 5mm or 6mm x 6mm wettable-flanks QFN package. The small package is perfect for space-constrained applications including infotainment head unit, telematics modules or ADAS. It offers 100Mbps transmit and receive capability across a single UTP, exceeds automotive electromagnetic interference demands and is Grade 1 (-40C to +125C) automotive AEC-Q100 qualified. Also, the device is Microchip Functional Safety Ready; it is specially created to simplify customers’ end-product ISO26262 safety certification with the support of specialised hardware safety features, FMEDA and safety manual.

The LAN8770M and LAN8770R support communication with an Ethernet MAC via standard MII/RMII and MII/RMII/RGMII interfaces, respectively. An optional 125MHz or 50MHz reference clock output is also offered for RGMII and RMII applications, often allowing removal of an external reference clock.

“Typically, an automotive module can only consume 100 microamps maximum in sleep (battery) mode so, if the PHY alone consumes north of 50 microamps, additional circuitry is required to avoid exceeding the target power budget,” said Charles Forni, vice president of Microchip’s USB and Networking business unit. “Often, applications add an additional wire or CAN bus just to enable and disable the power. Our PHY avoids such a need, minimising components, installation and cost.”