78Q2120

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 full-featured auto-negotiation function
Full duplex operation capable
PCS Bypass supports 5-bit symbol interface
Dual speed clock recovery 
Automatic polarity correction during auto-negotiation 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
 


Pinout




Specifications

PARAMETER	RATING
DC Supply Voltage	7 VDC
Storage Temperature	-65 to 150 °C
Pin Voltage	-0.3 to (Vcc+0.3) VDC
Pin Current	± 100 mA

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 pulse-shaper and a low-power line driver. The receiver has an adaptive equalizer and a baseline restoration circuit required for accurate clock and data recovery. The transceiver of the 78Q2120 interfaces to Cate gory-5 unshielded twisted pair (Cat-5 UTP) cabling, and is connected to the line media via 1:1 isolation transformers. No external filter is required. Interface to the MAC is accomplished through an IEEE
-802.3 compliant media independent interface (MII). The 78Q2120 is fabricated in a BiCMOS process for high performance and low power operation, and can operate from a single 3.3 V or 5 V supply.