Signal
Ethernet Controller (PHY / MAC)
Network interface ICs bridging digital data to twisted-pair copper.
What is it?
An Ethernet controller is either a PHY (Physical layer, copper or fiber line driver) or a MAC+PHY combo. The PHY handles the analog magic — magnetic coupling, line equalisation, auto-negotiation. The MAC handles framing, addressing, and bus interface (RGMII, MII, SGMII) to the host processor. Used in any device needing wired network connectivity — routers, switches, embedded systems, IoT gateways.
When do you need it?
- Adding 10/100/1000 Mbps Ethernet to a host SoC that has MII but no integrated PHY.
- Multi-port industrial switches (need multiple PHYs).
- Embedded gateways and IoT bridges.
- Energy-management and building-automation controllers (BACnet-IP over Ethernet).
How to pick the right one
- Speed
- 10 Mbps (legacy), 100 Mbps (common embedded), 1000 Mbps (consumer / industrial), 2.5/5/10 Gbps (server / datacenter).
- Host interface
- MII / RMII (10/100), GMII / RGMII / SGMII (Gigabit). Match to host MAC.
- PHY only or MAC+PHY
- PHY-only if host SoC has integrated MAC (most do). MAC+PHY for designs without MAC.
- PoE support
- Some PHYs integrate PoE-PD controllers; others need an external PD controller.
- Energy Efficient Ethernet (EEE)
- Supported in most modern PHYs — reduces power during idle.
- Operating temperature
- Industrial -40 to +85°C, automotive -40 to +125°C with AEC-Q100.
What Magnias offers
Magnias Ethernet controller portfolio covers 10/100 and 10/100/1000 PHYs for embedded / IoT / industrial applications, with consumer and AEC-Q100 automotive variants. Consult your FAE for the latest recommendation.
Common questions
Do I need magnetics?
Yes — Ethernet over copper needs isolation magnetics between PHY and the RJ45 connector. Many modern RJ45 jacks have integrated magnetics.
PHY vs MAC+PHY for an SoC project?
Most modern SoCs have integrated MAC, so a PHY-only chip is enough. Older SoCs without MAC need MAC+PHY combo IC.
How long can an Ethernet cable be?
Standard CAT5e/6 spec is 100 m per segment. Longer needs a switch in the middle, or fiber.