Philips sb8392c DATASHEETS

Philips Semiconductors Product specification

NE8392CCoaxial transceiver interface for Ethernet/Thin Ethernet

1995 May 1 853-1693 15180

DESCRIPTION

The NE8392C Coaxial Transceiver Interface (CTI) is a bipolar coaxial line driver/receiver for Ethernet (10base5) and Thin Ethernet (10base2) local area networks. The CTI is connected between the coaxial cable and the Data Terminal Equipment (DTE) and consists of a receiver, transmitter, receive-mode collision detector, heartbeat generator and jabber timer (see Block Diagram). The transmitter output connects directly to a doubly terminated 50Ω cable, while the receiver output, collision detector output and transmitter input are connected to the DTE through isolation transformers. Isolation between the CTI and the DTE is an IEEE 802.3 requirement that can be met on signal lines by using a set of pulse transformers normally available in a standard 16-pin DIP. Power isolation for the CTI is achieved using DC-to-DC conversion through a power transformer (see Figure 1, Connection Diagram).

During transmission the jabber timer is initiated to disable the CTI transmitter in the event of a longer than legal length data packet. Receive-mode collision detection circuitry monitors the signals on the coaxial cable to determine the presence of colliding packets and signals the DTE in the event of a collision. At the end of every transmission the heartbeat generator creates a pseudo collision for a short time to ensure that the collision circuitry is functioning correctly. The heartbeat function can be disabled for repeater applications.

The CTI is normally part of a three chip set that implements a complete Ethernet/ Thin Ethernet network interface for a DTE (see Figure 2, Interface Diagram). The other chips are a Serial Network Interface (SNI) and a Network Interface Controller (NIC). The SNI provides Manchester Encoding and Decoding while the NIC handles the media access protocol and buffer management tasks.

FEATURES

•Compatible with Ethernet II IEEE 802.3 10base5 and 10base2,

and ISO 8802/3 interface specifications

•100% drop-in compatible with industry standard 8392 sockets

•Integrates all transceiver electronics except signal and power

isolation

•Only one external resistor required for setting coaxial signaling

current

•Jabber timer function integrated on chip

•Heartbeat generator can be externally disabled for operation as

IEEE 802.3 compatible repeaters

PIN CONFIGURATION

CD+ 1

CD– 2

RX+ 3

RX– 6

TX+ 7

TX– 8

16 CDS

15 TXO

14 RXI

13 V

12 RR–

11 RR+

10 GND

9 HBE

N PACKAGE

1234

5 6 7 8

9 10 11

12 13 14 15 16 17 18

262728

RR–

RX+

CD–

CD+

CDS

TXO

N/C

RXI

RX–

TX+

TX–

HBE

GND

RR+

A PACKAGE

SD00283

•On-chip precision voltage reference for receive mode collision

detection

•Squelch circuitry on all signal inputs rejects noise

•Full ESD protection

•Standard 16-pin DIP and 28-pin PLCC packages

•Power-on reset prevents glitches on coaxial cable during power

up.

•Also available in advanced low-power BiCMOS technology. (See

selection chart and data sheets for the NE83C92, NE83Q92 or NE83Q93 for appropriate optimal usages)

ORDERING INFORMATION

DESCRIPTION TEMPERATURE RANGE ORDER CODE DWG #

16-Pin Plastic Dual In-Line Package (DIP)

0 to +70°C

NE8392CN SOT28-4

28-Pin Plastic Lead Chip Carrier (PLCC)

0 to +70°C

NE8392CA SOT261-3

Philips Semiconductors Product specification

NE8392CCoaxial transceiver interface for Ethernet/Thin Ethernet

1995 May 1

PIN DESCRIPTIONS

PIN NO.

N PKG

PIN NO.

PLCC

SYMBOL DESCRIPTION

1 2

2 3

CD+ CD–

Collision Outputs. Balanced differential line driver outputs which send a 10MHz oscillation signal to the DTE in the event of a collision, jabber interrupt or heartbeat test.

3 6

RX+ RX–

Receiver Outputs. Balanced differential line driver outputs which send the received signal to the DTE.

7 8

13 14

TX+ TX–

Transmitter Inputs. Balanced differential line receiver inputs which accept the transmission signal from the DTE and apply it to the coaxial cable at TXO once it meets Tx squelch threshold.

9 15 HBE

Heartbeat Enable. The heartbeat function is disabled when this pin is connected to VEE and enabled when connected to GND or left floating.

11 12

18 19

RR+ RR–

External Resistor. A 1kΩ (1%) resistor connected between these pins establishes the signaling current at TXO. RR– is internally connected to V

14 26 RXI

Receiver Input. This pin is connected directly to the coaxial cable. Received signals are equalized, amplified, and sent to the DTE through the RX+ pins once it meets Rx squelch threshold.

15 28 TXO

Transmitter Output. This pin is connected directly (Thin Ethernet) or through an external isolating diode (Ethernet) to the coaxial cable.

16 1 CDS

Collision Detect Sense. Ground sense connection for the collision detection circuitry. This pin should be directly connected to the coaxial cable shield to prevent ground drops affecting the collision threshold voltage.

16 17

GND Positive Supply Pin.

4 5

5 to 11

20 to 25

Negative supply pins. These pins also serve as a low thermal resistance path for extracting heat from the die. They should, therefore, be connected to a large metal area on the PC board.

NOTE:

1. The IEEE 802.3 name for CD is CI; for RX is DI; for TX is DO.

ABSOLUTE MAXIMUM RATINGS

SYMBOL PARAMETER RATING UNIT

Supply voltage

–12 V

Voltage at any input

0 to –12 V

STG

Storage temperature range –65 to +150

°C

SOLD

Lead soldering temperature (10sec.) +300

°C

Recommended max junction temperature

+130

°C

Thermal impedance (N and A packages) 60

°C/W

NOTE:

1. 100% measured in production.

2. The junction temperature is calculated from the following expression: T

= TA + θ

[VEE (0.08 + n x 0.05/100) + 8(VEE –2) / R]

where

= Ambient temperature in °C.

= Thermal resistance of package.

= Normal operating supply voltage in volts. n = Percentage transmitter duty cycle. R = Pull down resistors on the RX and CD pins in Ω.

The N package is specially designed to have a low θ

by directly connecting the four center Pins 4, 5, 12, and 13 to the die attachment area.

These four pins then provide a conductive heat flow path from the die to the PCB where they should be soldered to a large area V

track. For

the A package, Pins 5 to 11 and 19 to 25 should similarly be soldered to a large area V

and rack.

Philips Semiconductors Product specification

NE8392CCoaxial transceiver interface for Ethernet/Thin Ethernet

1995 May 1

BLOCK DIAGRAM

RECEIVER

AC–DC SQUELCH

TRANSMITTER

SQUELCH

COLLISION

COMPARATOR

& HEARTBEAT GENERATOR

JABBER

TIMER

RECEIVER

EQUALIZER

4–POLE BESSEL

LOW PASS FILTER

SENSE BUFFER

10MHz

OSC

LINE

DRIVER

COAX

CABLE

BUFFER

LINE

DRIVER

HEARTBEAT ENABLE

COLLISION

PAIR

(CD+, CD–)

TRANSMIT

PAIR

(TX+, TX–)

RECEIVE

PAIR

(RX+, RX–)

DTE

INTERFACE

RXI

TXO

CDS

SD00274

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