Use this spacing tool to set the spacing between your traces for a 90 ohm differential pair - Use "JLC3313" 4 layer stackup - Route on Top with L2 reference or Bottom with L3 reference - Trace width of both traces should be 200um

Small Footprint RMII 10/100 Ethernet Transceiver with HP Auto-MDIX Support LAN8720A-CP-TR-ABC is a low-power, single-port 10BASE-T/100BASE-TX Ethernet Physical Layer (PHY) transceiver from Microchip Technology. It is designed to connect a microcontroller, processor, or Ethernet MAC to a standard Ethernet network through an RMII (Reduced Media Independent Interface). The device is widely used in embedded networking applications such as industrial controllers, IoT gateways, IP cameras, networked printers, routers, and ESP32-based Ethernet designs. Key Features Single-chip 10/100 Mbps Ethernet PHY Supports both 10BASE-T and 100BASE-TX Ethernet operation. RMII Interface Reduced pin-count interface for easy connection to Ethernet MACs and microcontrollers. IEEE 802.3 / 802.3u Compliant Fully compliant with Fast Ethernet standards. HP Auto-MDIX Support Automatically detects and configures straight-through or crossover Ethernet cables. Auto-Negotiation Automatically selects the best available speed and duplex mode. Flexible I/O Voltage Supports LVCMOS I/O voltages from 1.6 V to 3.6 V, simplifying interfacing with different processors. Integrated 1.2 V Regulator Allows operation from a single 3.3 V supply, reducing external components. Low-Power Architecture Features multiple power-saving modes through Microchip's flexPWR® technology. Built-in Diagnostics and Reliability Features Loopback modes, automatic polarity correction, link-status monitoring, and wake-up detection. Compact Package Available in a 24-pin SQFN/QFN (4 mm × 4 mm) package for space-constrained designs #CommonPartsLibrary #IntegratedCircuit