Ethernet PHY - Transformerless Application Notes for Microchip's KSZ and LAN Devices
Transformerless application schematic configuration for KSZ and LAN devices are different. You should base your design on two distinct application notes.
- For KSZ devices, refer to "ANLAN120 - Capacitive Coupling Ethernet Transceivers without Using Transformers". It shows a mix of both, namely: Voltage Mode and Current Mode Capacitive Coupling.
- For LAN devices, refer to "AN2190 - Transformerless Applications of Microchip's Ethernet Devices".
Whenever you implement a magnetic-less interface, we recommend operating the link under the following conditions:
- 100 BASE-TX,
- full duplex operation with auto-negotiation disabled,
- and auto MDIX disabled on both sides of the link.
These allow the link to operate in the most reliable and stable mode for your design.