DP8392C

Features:

Compatible with Ethernet II, IEEE 802.3 10Base5 and 10Base2 (Cheapernet)
Integrates all transceiver electronics except signal & power isolation
Innovative design minimizes external component count
Jabber timer function integrated on chip
Externally selectable CD Heartbeat allows operationwith IEEE 802.3 compatible repeaters
Precision circuitry implements receive mode collision detection
Squelch circuitry at all inputs rejects noise
Designed for rigorous reliability requirements of IEEE 802.3
Standard Outline 16-pin DIP uses a special leadframe that significantly reduces the operating die temperature



Description

The DP8392C Coaxial Transceiver Interface (CTI) is a coaxial cable line driver/receiver for Ethernet/Thin Ethernet
(Cheapernet) type local area networks. The CTI (DP8392C) is connected between the coaxial cable and the Data Terminal Equipment (DTE). In Ethernet applications the transceiver is usually mounted within a dedicated enclosure and is connected to the DTE via a transceiver cable. In Cheapernet applications, the CTI (DP8392C) is typically located within the DTE and connects to the DTE through isolation transformers only. The CTI (DP8392C) consists of a Receiver, Transmitter, Collision Detector,
and a Jabber Timer. The Transmitter connects directly to 50 ohm coaxial cable where it is used to drive the coax
when transmitting. During transmission, a jabber timer is initiated to disable the CTI (DP8392C) transmitter in the event of a longer than legal length data packet. Collision Detection circuitry monitors the signals on the coax to determine the presence of colliding packets and signals the DTE in the event of collision.
The CTI (DP8392C) is part of a three chip set that implements the complete IEEE 802.3 compatible network node electronics as
shown below. The other two chips are the DP8391 Serial Network Interface (SNI) and the DP8390 Network Interface
Controller (NIC).
The SNI provides the Manchester encoding and decoding functions; whereas the NIC handles the Media Access Protocol and the buffer management tasks. Isolation between the CTI (DP8392C) and the SNI is an IEEE 802.3 requirement that can be easily satisfied on signal lines using a set of pulse transformers that come in a standard DIP. However, the power isolation for the CTI is done by DC-to-DC conversion through a power transformer.