Product Summary

The 78Q2120C-CGT 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 function. 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 78Q2120C-CGT interfaces to Category-5 unshielded twisted pair (Cat-5 UTP) cabling for 100BASE-TX/10BASE-T and Category-3 unshielded twisted pair for 10BASE-T. Connection to the line media is via 1:1 isolation transformers.

Parametrics

78Q2120C-CGT absolute maximum ratings: (1)DC Supply Voltage (Vcc): -0.5 to 4.0 VDC; (2)Storage Temperature: -65 to 150℃; (3)Pin Voltage (CMOS inputs): -0.3 to 5.5 VDC; (4)Pin Voltage (CMOS outputs except TXOP/N): -0.3 to (Vcc+0.6) VDC; (5)Pin Voltage (TXOP/N only): -0.3 to (Vcc+1.4) VDC; (6)Pin Current: ± 120 mA.

Features

78Q2120C-CGT features: (1)10BASE-T/100BASE-TX IEEE-802.3 compliant TX and RX functions requiring a dual 1:1 isolation transformer interface to the line; (2)Integrated MII, 10BASE-T/100BASE-TX ENDEC, 100BASE-TX scrambler/descrambler, and fullfeatured auto-negotiation function; (3)Full duplex operation capable; (4)PCS Bypass supports 5-bit symbol interface; (5)Register-programmable transmit amplitude; (6)Dual speed digital clock recovery; (7)Automatic polarity correction during autonegotiation and 10BASE-T signal reception; (8)Power-saving and power-down modes including transmitter disable; (9)LED indicators: LINK, TX, RX, COL, 100, 10, FDX; (10)User programmable Interrupt pin; (11)64-Pin TQFP (JEDEC LQFP) package; (12)Single 3.3 V ?0.3V Supply.

Diagrams

78Q2120C-CGT block diagram

78Q2120
78Q2120
Other

Data Sheet
Negotiable 
78Q2120C09-64CGT/F
78Q2120C09-64CGT/F
Maxim Integrated Products
Ethernet ICs 10-100 Fast Ethernet Transceiver
Data Sheet
0-1: $4.29
1-25: $2.88
25-50: $2.09
50-100: $2.00
78Q2120C09-64CGTR/F
78Q2120C09-64CGTR/F

TXRX 10/100 BASE 3.3V 64-LQFP
Data Sheet
Negotiable 
78Q2120C09-CGTR/F
78Q2120C09-CGTR/F
Maxim Integrated Products
Ethernet ICs 10-100 Fast Ethernet Transceiver
Data Sheet
0-1175: $1.88
1175-1500: $1.88
78Q2120C09-DB
78Q2120C09-DB
Maxim Integrated Products
Ethernet Development Tools 78Q2120C09 Demo Boa
Data Sheet
0-1: $65.50
1-2: $64.26
2-5: $62.22
78Q2123/F
78Q2123/F
Maxim Integrated Products
Ethernet ICs 10/100 Fast Ethernet MicroPHY
Data Sheet
0-1: $1.27
1-25: $0.85
25-50: $0.62
50-100: $0.59