7.7 Clock Circuit

For MII and SC-MII operation, the LAN8670 and LAN8672 require a 25 MHz clock source, either a crystal or single-ended clock oscillator. For RMII operation, the LAN8670 and LAN8671 require a 50 MHz single-ended clock oscillator. In all cases, the clock source must be ± 100 ppm or better tolerance.