DESCRIPTION
The 78Q2120 is a 10BASE-T/100BASE-TX Fast Ethernet transceiver. It includes integrated MII, ENDECs, scrambler/descrambler, dual-speed clock recovery, and full-featured auto-negotiation functions. The transmitter includes an on-chip pulseshaper and a low-power line driver. The receiver has an adaptive equalizer and a baseline restoration circuit required for accurate clock and data recovery.

FEATURES
• 10BASE-T/100BASE-TX IEEE-802.3 compliant TX and RX functions requiring a dual 1:1 isolation transformer interface to the line
• Integrated MII, 10BASE-T/100BASE-TX ENDEC, 100BASE-TX scrambler/descrambler, and fullfeatured auto-negotiation function
• Full duplex operation capable
• PCS Bypass supports 5-bit symbol interface
• Dual speed clock recovery
• Automatic polarity correction during autonegotiation and 10BASE-T signal reception
• Power-saving and power-down modes including transmitter disable
• BiCMOS technology, operates with a single 3.3V or 5V supply
• LED indicators: LINK,TX,RX,COL,100,10,FDX
• User programmable Interrupt pin
• General Purpose I/O Interface (80-pin package only)
• 64 and 80-Lead TQFP (JEDEC LQFP), 64-Pin QFP packages