78Q8392L-28CH ETC [List of Unclassifed Manufacturers], 78Q8392L-28CH Datasheet - Page 3

• Manufacturer Part Number: 78Q8392L-28CH
• Description: Low Power Ethernet Coaxial Transceiver
• Manufacturer: ETC [List of Unclassifed Manufacturers]

JABBER FUNCTION
When valid data on the TX± pins detected, the jabber
timer is started. If there is valid data for more than 20
ns, a latch is set which disables the transmitter
output and enables the 10 MHz output on the CD±
pins. The latch is reset within 0.5 seconds after the
valid data is removed from the transmitter input
(TX±). This action resets the jabber timer and
disables the 10 MHz CD output. The TX± inputs
must remain inactive during the 0.5 second reset
period.
DATA MEDIA
CDS
TXO
RXI
OUTPUT DRIVER
RECEIVER
BUFFER
TRANSMIT
INPUT
TX ON
FIGURE 1: 78Q8392L General System Block Diagram
LP FILTER
EQUALIZER
THRESHOLD
COLLISION
CONTROL LOGIC
HEART BEAT TIMER
BLANKING TIMER
JABBER TIMER
THRESHOLD
SQUELSH
COMPARATOR
SLICER
SQUELCH
COMPARATOR
COLLISION
END TRANSMIT
NARROW
TX DATA VALID
TX± DISABLE
PULSE
FILTER
SHAPING
3
CD ± ON
PULSE
FILTER
HEARTBEAT FUNCTION
The 10 MHz CD outputs are enabled for about 1 µs
at approximately 1.1 µs after the end of each
transmission. The heartbeat signal tells the DTE that
the circuit is functioning. This is implemented by
starting the heartbeat timer when the valid data
signal indicates the end of a transmission. This
function is disabled when HBE pin is tied to V
TRANSITION
PERIOD
TAMER
TRANSITION
TRANSITION
PERIOD
TIMER
TIMER
END
RX DATA
10 MHz
OSC
VALID
SLICER
NARROW
PULSE
FILTER
ENABLE
TX ± < -250 mV
TX ± > -250 mV
Low Power Ethernet
BUFFERED TX
Coaxial Transceiver
AND CURRENT
REFERENCE
REFERENCE
BANDGAP
RX+
RX-
PRESET
DETECT
SIGNAL
COMPARATOR
78Q8392L
ENABLE
TRANSMIT INPUT
BUFFER
TX DISABLE
CD+
CD-
RR+
RR-
TX+
TX-
EE.