www.DataSheet4U.com KS8721B/BT Micrel KS8721B/B.
KS8721BT - 2.5V 10/100BasTX/FX MII Physical Layer Transceiver
KS8721BL - 3.3V 10/100 BASE-TX/FX PHYSICAL LAYER TRANSCEIVER
KS8721B - 2.5V 10/100BasTX/FX MII Physical Layer Transceiver