RMII Ethernet PHY for 10/100Base-TX
The KSZ8081RNDCA-TR is a single-port 10/100Base-TX Ethernet physical-layer transceiver from Microchip Technology, using the Reduced Media Independent Interface (RMII) to connect directly to an RMII-capable MAC. It operates in full duplex mode with one driver and one receiver (1/1), handling both transmit and receive paths simultaneously. The supply voltage accepts 1.8V, 2.5V, or 3.3V, allowing the PHY to match the I/O voltage of the host MAC without a separate level translator. The commercial temperature grade (0°C to 70°C) limits the part to indoor, office, or consumer equipment — not for extended industrial or automotive environments.
Package and layout: 24-QFN with exposed pad
Housed in a 24-VFQFN exposed-pad package (4x4 mm body, 24-QFN supplier device package), the KSZ8081RNDCA-TR requires a thermal pad on the PCB to dissipate heat from the PHY. The exposed pad must be soldered to a ground plane with adequate thermal vias — the datasheet layout section (page 7) gives the recommended footprint and stencil aperture. Surface-mount assembly with tape-and-reel (TR) or cut-tape (CT) packaging is standard. The 0.50 mm pitch QFN demands careful solder-paste volume control; a 4-layer board with a solid ground plane under the pad is typical for thermal and signal-integrity reasons.
Active production and sourcing status
The part is ROHS3 compliant, meeting EU Directive 2011/65/EU. Sourcing is handled per RFQ against your BOM quantity — no stock-holding claim, but the active status means supply continuity is not at risk.