LAN8670/1

4.7.2 Reference Clock (REFCLKIN)

The REFCLKIN pin is used to connect an external 50.0 MHz reference clock source for RMII operation. The input reference clock must be between 1.8-3.3V amplitude. The clock source must become stable after the assertion of reset and remain stable to begin proper operation. In addition, the LAN8670 XTO pin must be unconnected and floating.

For reference clock requirements refer to the section RMII Clock Source - 50 MHz Oscillator.

Figure 4-6. RMII Reference Clock Oscillator Input

The online versions of the documents are provided as a courtesy. Verify all content and data in the device’s PDF documentation found on the device product page.