78Q8392L
Low Power Ethernet
Coaxial Transceiver
February 1998
DESCRIPTION
The 78Q8392L Ethernet Transceiver is a low power
BiCMOS coax line transmitter/receiver. The device
includes analog transmit and receive buffers, a 10
MHz on-board oscillator, timing logic for jabber and
heartbeat functions, output drivers and bandgap
reference, in addition to a current reference and
collision detector.
This transceiver provides the interface between the
single-ended coaxial cable signals and the
Manchester-encoded differential logic signals.
Primary functional blocks include the receiver,
transmitter, collision detection and jabber timer. This
IC may be used in either internal or external MAU
environments.
The 78Q8392L is available in 16-pin plastic and 28-
pin PLCC packages.
FEATURES
• Very low power consumption
• Compliant with Ethernet II, IEEE 802.3
10Base5 and 10Base2
• Integrates all transceiver functions except
signal and power isolation
• Innovative design minimizes external
components count and power consumption
• Jabber timer function integrated on chip
• Externally selectable CED heartbeat allows
operation with IEEE 802.3 compatible
repeaters
• Squelch circuitry at all inputs rejects noise
• Power-on reset and test modes
• Advanced BiCMOS process
CONNECT DIAGRAM
510 ±5%
x 4
CD+
CD–
RX+
RX–
TX+
TX-
COLLISION
SIGNAL
TO DTE
DATA TO
DTE
DATA FROM
DTE
VEE
VEE
GND
RR-
RR+
–9V
41
13
2
3
6
12
11
7
8
78
TXO
15
HBE
9
VEE
5
CDS
16
RXI
14
COAX
10