イーサネットPHY

KSZ8041NL-TR

KSZ8041NL-TR - 10/100 Ethernet PHY, MII/RMII, 32-QFN | Microchip

The Microchip KSZ8041NL-TR is a single-supply 10BASE-T/100BASE-TX physical layer (PHY) transceiver that provides MII and RMII MAC interfaces, housed in a 32-pin QFN (5x5 mm) package with HP Auto-MDIX support. The device operates from a single 3.3V supply (3.135V to 3.465V), supports 10/100 Mbps data rates per IEEE 802.3 and IEEE 802.3u, and integrates the line-side magnetics interface as well as baseline wander correction to extend signaling distance. A PHY (physical layer device) is the lowest tier of the Ethernet OSI stack, sitting just above the transformer/MDI and below the MAC layer. It handles line coding (MLT-3 / 4B5B), link training, auto-negotiation, and clock recovery. Within a typical embedded Ethernet design, a PHY sits between the magnetics plus RJ45 jack and an Ethernet MAC, either inside a microcontroller or as a separate controller; engineers select a discrete PHY when the host MCU/MAC lacks 10/100 support, when isolation or industrial temperature range is required, or when a broader MAC/PHY ecosystem has been validated for a given application. Key features of the KSZ8041NL-TR include 1/1 transceiver configuration with full MII and RMII MAC-side interfaces (SMII supported on the KSZ8041RNL version), HP Auto-MDIX crossover correction that eliminates the need for crossover cables, on-chip 1.8V regulator that can optionally power the MAC, low-power energy-detect mode, and linkMD cable diagnostics for opens, shorts, and cable length estimation. The mixed-signal design reportedly reduces power consumption versus competing 100 Mbps PHYs. Architecturally, the KSZ8041NL uses a DSP-based echo canceller and adaptive equalizer to achieve robust 100BASE-TX performance over CAT-5 cable, with HP Auto-MDIX implemented in the analog front end to autonegotiate polarity and pair roles. The MAC interface supports both MII (25 MHz reference clock at 100 Mbps) and RMII (50 MHz reference clock shared between MAC and PHY), enabling pin-compatible use with a wide range of microcontrollers. Typical applications include set-top boxes and IPTV gateways, network-capable printers and MFPs, industrial Ethernet sensors and PLCs, gaming consoles, and any embedded design that needs a 10/100 Ethernet port without a built-in PHY. The QFN-32 (5x5 mm) small footprint also suits space-constrained consumer and IoT appliances. When laying out this part, give the 50 MHz RMII clock trace a short, matched-length path to both the MAC and the PHY, and follow Microchip's KSZ8041NL Hardware Design Checklist for RJ45 magnetics pairing; do not skip the center-tap capacitor network on each line-side pair. This page compiles distributor pricing, drop-in alternatives, and PCB design notes not found in the bare datasheet, helping engineers select and place the KSZ8041NL-TR quickly.