Philips Semiconductors

Product specification

NE83Q92

Low-power coaxial Ethernet transceiver

1995 May 1

853-1737 15180

DESCRIPTION

The NE83Q92 is a low power BiCMOS coaxial transceiver interface
(CTI) 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 50

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. Power isolation for the
CTI is achieved using DC-to-DC conversion through a power
transformer (see Figure 1, Connection Diagram).

The part is fully pin compatible with the industry standard 8392, but
has substantially lower current consumption, is fully compliant with
the IEEE802.3 standard, and has additional features such as
optional pull-down resistors (Figure 1, Note 4), and automatic
selection between AUI and coaxial connections.

The NE83Q92 is manufactured on an advanced BiCMOS process
and is available with PLCC and SOL packages which make it ideally
suited to lap-top personal computers or systems where low power
consumption, limited board space and jumperless design is
required. Refer to selection flow chart for optimal apllication.

FEATURES

Fully compliant with Ethernet II, IEEE 802.3 10BASE-5 and
10BASE-2, and ISO 8802/3 interface specifications

100% drop-in compatible with industry standard 8392 sockets
(N & A options)

Optimal implementation can use 1 Watt DC-DC converter and
reduces external part count by not requiring external pull-down
resistors

High efficiency AUI drivers automatically power-down under idle
conditions to minimize current consumption

Automatically disables AUI drivers when no coaxial cable is
connected, allowing hard-wiring of AUI connection and
local/integrated CTI connection

Smart squelch on data inputs eliminates false activations

Advanced BiCMOS process for extremely low power operation

Available in 16-pin DIP, 16-pin SOL and both 20- and 28-pin
PLCC packages

Expanded version (NE83Q93) with 5 LED status drivers is
available for repeater and advanced system applications

Full ESD protection

Power-on reset prevents glitches on coaxial cable

PIN CONFIGURATION

CD+ 1

CD 2

RX+ 3

VEE

RX 6

TX+ 7

TX 8

16 CDS

15 TXO

14 RXI

13 VEE

12 RR

11 RR+

10 GND

9 HBE

D, N Packages

12 13

14 15 16 17 18

RX+

CD+

CDS

TXO

N/C

RXI

TX+

HBE

GND

RR+

A Packages

VEE

CD+

CDS

TXO

N/C

RXI

RR+

TX+

HBE

GND

RX+

SD00302

ORDERING INFORMATION

DESCRIPTION

TEMPERATURE RANGE

ORDER CODE

DWG #

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

0 to +70

NE83Q92N

SOT28-4

16-Pin Plastic Small Outline Large (SOL) Package

0 to +70

NE83Q92D

SOT162-1

20-Pin Plastic Leaded Chip Carrier (PLCC) Package

0 to +70

NE83Q92A20

SOT380-1

28-Pin Plastic Leaded Chip Carrier (PLCC) Package

0 to +70

NE83Q92A

SOT261-3

Philips Semiconductors

Product specification

NE83Q92

Low-power coaxial Ethernet transceiver

1995 May 1

PIN DESCRIPTIONS

PIN NO.

N PKG

PIN NO.

PLCC-20

PIN NO.

PLCC-28

SYMBOL

DESCRIPTION

1
2

2
3

CD+
CD

Collision Outputs. Balanced differential line driver outputs which send a 10MHz signal to the
DTE in the event of a collision, jabber interrupt or heartbeat test. External pull-down resistors
are optional.

3
6

4
8

RX+
RX

Receiver Outputs. Balanced differential line driver outputs which send the received signal to
the DTE. External pull-down resistors are optional.

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, if it meets Tx squelch threshold.

HBE

Heartbeat Enable. The heartbeat function is disabled when this pin is connected to V

and

enabled when connected to GND or left floating.

14
15

18
19

RR+
RR

External Resistor. A 1k

(1%) resistor connected between these pins establishes the

signaling current at TXO.

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, if it meets Rx squelch

threshold.

TXO

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

CDS

Collision Detect Sense. Ground sense connection for the collision detection circuitry. This
pin should be connected directly to the coaxial cable shield for standard Ethernet operation.

16
17

GND

Positive Supply Pin.

4
5

5 7

16 17

5 to 11

20 to 25

Negative supply pins.

N/C

Not used.

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

Philips Semiconductors

Product specification

NE83Q92

Low-power coaxial Ethernet transceiver

1995 May 1

RECEIVER

ACDC SQUELCH

TRANSMITTER

SQUELCH

COLLISION

COMPARATOR

HEARTBEAT

GENERATOR

JABBER

TIMER

RECEIVER

EQUALIZER

4POLE 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

ABSOLUTE MAXIMUM RATINGS

SYMBOL

PARAMETER

RATING

UNIT

Supply voltage

Voltage at any input

0 to 12

STG

Storage temperature range

65 to +150

SOLD

Lead soldering temperature (10sec.)

+300

Recommended max junction temperature

+150

Thermal impedance (N and A packages)

C/W

NOTE:
1. 100% measured in production.
2. The junction temperature is calculated from the following expression:

= T

[(V

x 0.015 x n

IDL

) + (V

x 0.027 x n

) + (V

x 0.075 x n

)]

where

= Ambient temperature in

= Thermal resistance of package.

= Normal operating supply voltage in volts.

IDL

= Percentage of duty cycle idle

= Percentage of duty cycle receiving

= Percentage of duty cycle transmitting

Philips Semiconductors

Product specification

NE83Q92

Low-power coaxial Ethernet transceiver

1995 May 1

ELECTRICAL CHARACTERISTICS

= 9V

6%; T

= 0

C to +70

C unless otherwise specified

1,2

. No external isolation

LIMITS

SYMBOL

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNIT

UVL

Under voltage lockout. Transceiver disabled for
|V

| < |V

UVL

7.5

Supply current idle

Supply current transmitting (without collision)

Without external

pull-down resistors

RXI

Receive input bias current

RXI

= 0V

+25

CDS

Cable sense input bias current

CDS

= 0V

HBE input HIGH voltage

+2.4

HBE input LOW voltage

+1.6

HBE input HIGH current

HBE

= 0V

+10

HBE input LOW current

HBE

= V

TDC

Transmit output DC current level

TAC

Transmit output AC current level

TDC

TX10

Transmit current

TXO

= 10V

250

+250

TCOM

Transmitter output voltage compliance

3.7

Collision threshold

Measured by applying

DC voltage at RXI

(CDS = 0V)

1450

1530

1580

DIS

AUI disable voltage at RXI

Measured as DC

voltage at RXI

3.5

Differential output voltage non idle at RX+ and
CD

600

1100

Differential output voltage imbalance idle at
RX

and CD

Output common mode voltage at RX

and CD

RXI = 0V

4.0

5.5

7.0

Receiver squelch threshold

RXI

average DC

(CDS = 0V)

150

250

350

Transmitter squelch threshold

TX+

) peak

175

225

275

RXI

Shunt resistance at RXI nontransmitting

100

RXI

Input capacitance at RXI

TXO

Shunt resistance at TXO transmitting

7.5

AUIZ

Differential impedance at RX

and CD

with no

coaxial cable connected

Differential impedance at TX

NOTES:
1. Currents flowing into device pins are positive. All voltages are referenced to ground unless otherwise specified. For ease of interpretation,

the parameter limit that appears in the MAX column is the largest value of the parameter, irrespective of sign. Similarly, the value in the MIN
column is the smallest value of the parameter, irrespective of sign.

2. All typical values are for V

= 9V and T

= 27

3. I

TDC

is measured as (V

MAX

+ V

MIN

)/(2 x 25) where V

MAX

and V

MIN

are the max and min voltages at TXO with a 25

load between TXO and

GND. I

TAC

is measured as (V

MAX

MIN

)/(2 x 25).

4. The TXO pin shall continue to sink at least I

TDC

min when the idle (no signal) voltage on this pin is 3.7V.

5. Collision threshold for an AC signal is within 5% of V

6. Measured on secondary side of isolation transformer (see Connection Diagram, Figure NO TAG). The transformer has a 1:1 turns ratio with

an inductance between 30 and 100

H at 5MHz.

7. Measured as the voltage difference between the RX pins or the CD pins with the transformer removed.
8. Not 100% tested in production.

Philips Semiconductors

Product specification

NE83Q92

Low-power coaxial Ethernet transceiver

1995 May 1

TIMING CHARACTERISTICS

= 9V +6%; T

= 0 to 70

C, unless otherwise specified

. No external isolation diode on TXO.

LIMITS

SYMBOL

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNIT

RON

Receiver start up delay RXI to RX

(Figure 3)

First received bit on RX

RXI

= 2V peak

bits

First validly timed bit on RX

RON

bits

Receiver prop. delay RXI to RX

RXI

= 2V peak

Differential output rise time on RX

and CD

2,3

Differential output fall time on RX

and CD

2,3

Differential output settling time on RX

and CD

to V

= 40mV

(see Figure 4)

Receiver and cable total jitter

RHI

Receiver high to idle time

Measured to +210mV

200

850

Rise and fall time matching on RX+ and CD+

0.1

TST

Transmitter startup delay TX

to TXO (Fig. 5)

First transmitted bit on TXO

+ = 1V peak

bits

First validly timed bit

TST

+ 2

bits

Transmitter prop delay TX

to TXO

(see Figure 5)

+ = 1V peak

Transmitter rise time 10% to 90% (see Figure 5)

Transmitter fall time 10% to 90% (see Figure 5)

mismatch

Transmitter added skew

4,5

TON

Transmitter turn on pulse width (see Figure 5)

= 1V peak

TOFF

Transmitter turn off pulse width (see Figure 5)

+ = 1V peak

125

200

CON

Collision turn on delay (see Figure 6)

0V to 2V step at RXI

bits

COFF

Collision turn off delay (see Figure 6)

2V to 0V step at RXI

bits

CHI

Collision high to idle time (see Figure 6)

Measured to +210mV

200

850

Collision frequency (see Figure 6)

8.5

11.5

MHz

Collision signal pulse width (see Figure 6)

HON

Heartbeat turn on delay (see Figure 7)

0.6

1.6

Heartbeat test duration (see Figure 7)

0.5

1.5

Jabber activation delay measured from TX

(see Figure 8)

Jabber reset delay measured from TX

to CD

(see Figure 8)

250

650

NOTES:
1. All typical values are for V

= 9V and T

= 27

2. Measured on secondary side of isolation transformer (see Figures NO TAG and 1, Connection Diagram). The transformer has a 1:1 turn

ratio with an inductance between 30 and 100

H at 5MHz.

3. The rise and fall times are measured as the time required for the differential voltage to change from 225mV to +225mV, or +225mV to

225mV, respectively.

4. Difference in propagation delay between rising and falling edges at TXO.
5. Not 100% tested in production.

Philips Semiconductors

Product specification

NE83Q92

Low-power coaxial Ethernet transceiver

1995 May 1

FUNCTIONAL DESCRIPTION

The NE83Q92 is a low power BiCMOS coaxial Ethernet transceiver
which complies with the IEEE 802.3 specification and offers the
following features:

1. Low current consumption of typically 15mA when idle and 80mA

while transmitting (without collision) allows smaller DC-DC
converter to be used for the isolated power supply, (no external
pull-down resistors).

2. Automatic selection between AUI cable and coaxial connections

by placing the AUI outputs in a high impedance state when the
coaxial cable is disconnected. This eliminates the need for
changing a jumper position on the Ethernet board when selecting
either Thin Ethernet or remote transceiver connections.

3. High efficiency AUI drivers for the RX

and CD

ports

automatically power down when idling and are powered-up when
a receive signal is detected. This is very important/useful for
power sensitive applications such as lap-top computers or
PCMCIA cards.

4. The NE83Q92 advanced AUI driver (RX

and CD

) design

requires no external pull-down resistors (500

) to drive a

terminated (78

) AUI cable and still meets the IEEE 802.3

specification. The drivers will also operate correctly if external
resistors are present, so that they can be retro-fitted into existing
8392 designs. However, an extra current of 7mA/output (for
500

resistors) would be generated, by these resistors,

regardless of whenther the transceiver is idle or responding to
traffic.

Receiver Functions

The receiver consists of an input buffer, a cable equalizer, a 4-pole
Bessel low pass filter, a squelch circuit and a differential line driver.

The buffer provides high input resistance and low input capacitance
to minimize loading and reflections on the coaxial cable.

The equalizer is a high pass filter that compensates for the low pass
effect of the coaxial cable and results in a flatband response over all
signal frequencies to minimize signal distortion.

The 4-pole Bessel low pass filter extracts the average DC voltage
level on the coaxial cable for use by the receiver squelch and
collision detection circuits.

The receiver squelch circuit prevents noise on the coaxial cable
from falsely triggering the receiver in the absence of a true signal.
At the beginning of a packet, the receiver turns on when the DC
level from the low pass filter exceeds the DC squelch threshold and
the received packet has started with a 01 bit sequence with
acceptable timing parameters. For normal signal levels this will take
less than 500ns, or 5 bits. However, at the end of a packet, a fast
receiver turn off is needed to reject both dribble bits on the coaxial
cable and spurious responses due to settling of the on-chip
bandpass filter. This is accomplished by an AC timing circuit that
disables the receiver if the signal level on the coaxial cable remains
high for typically 250ns and only enables the receiver again after
approximately .5

s. Figures 3 and 4 illustrate receiver timing.

The differential line drivers provide typically +900mV signals to the
DTE with less than 7ns rise and fall times. When in idle state (no
received signal) their outputs provide <20mV differential voltage
offset to minimize DC standing current in the isolation transformer.

Transmitter Functions

The transmitter has differential inputs and an open collector current
driver output. The differential input common mode voltage is
established by the CTI and should not be altered by external
circuitry. Controlled rise and fall times of 25ns (

5ns) minimize

higher harmonic components in the transmitted spectrum, while
matching of these rise and fall times to typically 2ns minimizes
signal jitter. The drive current levels of the CTI are set by an on-chip
bandgap voltage reference and an external 1% resistor. An on-chip
isolation diode is provided to reduce the transmitter's coaxial cable
load capacitance. For Thin Ethernet applications, no further external
isolation diode is required, since the NE83Q92 meets the capacitive
loading specifications. For Ethernet applications a further external
diode should be added to reduce loading capacitance.

The transmitter squelch circuit ensures that the transmitter can only
be enabled if the transmitted packet begins with a 01 bit sequence
where the negative-going differential signals are typically greater
than 225mV in magnitude and 25ns in duration.

The transmitter will be disabled at the end of a packet if there are no
negative going signals of greater than 225mV for more than typically
150ns. Figure 5 illustrates transmitter timing.

Collision Functions

The collision detection scheme implemented in the NE83Q92 is
receive mode detection, which detects a collision between any two
stations on the network with certainty at all times, irrespective of
whether or not the local DTE is producing one of the colliding
signals. This is the only detection scheme allowed by the IEEE
802.3 standard for both repeater and non-repeater nodes.

The collision circuitry consists of the 4-pole Bessel low pass filter, a
comparator, a precision voltage reference that sets up the collision
threshold, a heartbeat generator, a 10MHz oscillator, and a
differential line driver.

The collision comparator monitors the DC level at the output of the
low pass filter and enables the line driver if it is more negative than
the collision threshold. A collision condition is indicated to the DTE
by a 10MHz oscillation signal at the CD outputs and typically occurs
within 700ns of the onset of the collision. The collision signal begins
with a negative-going pulse and ends with a continuous high-to-idle
state longer than 170ns. Figure 6 illustrates collision timing.

At the end of every transmission, the heartbeat generator creates a
pseudo collision to ensure that the collision circuitry is properly
functioning. This pseudo collision consists of a 1

s burst of 10MHz

oscillation at the line driver outputs approximately 1

s after the end

of the transmission. The heartbeat function can be disabled
externally by connecting the HBE (heartbeat enable) to V

. This

allows the CTI to be used in repeater applications. Figure 7
illustrates heartbeat timing.

Jabber Functions

The jabber timer monitors the transmitter and inhibits transmission if
it is active for longer than typically 30ms. The jabber circuit then
enables the collision outputs for the remainder of the data packet
and for typically 450ns (unjab time) after it has ended. At this point
the transmitter becomes uninhibited. Figure 8 illustrates jabber
timing.

Philips Semiconductors

Product specification

NE83Q92

Low-power coaxial Ethernet transceiver

1995 May 1

Power-On Reset/Under Voltage Lockout/AUI
Selection

The transmit and receive squelch circuits of the NE83Q92 remain
active if the absolute value of V

is less than the threshold for

under voltage lockout, V

UVL

. This prevents glitches from appearing

on either the AUI or coaxial cable during power up and power down.

There is no collision announcement during power up and the
transceiver waits for 400ms before becoming enabled.

If RXI is disconnected from the coaxial cable after power up, its
voltage will fall towards V

. If the absolute value of this voltage

exceeds the AUI disable voltage, V

DIS

, for longer than 800ms, the

transmit and receive squelch circuits remain active and, in addition,
the AUI drivers become high impedance. This permits AUI
connections to be hard wired together, e.g., the coaxial transceiver
and a 10BASE-T transceiver, with the signal path determined by
which transceiver is connected to its external cable.

There is a 400ms collision announcement on disconnecting RXI, but
there is no announcement on re-connection. This feature can be
disabled by pulling RXI up with a 200k

to ground.

Detection of Coaxial Cable Faults

In the NE83Q92 there is no internal loopback path from the TX
inputs to the RX outputs. This means that, when the local DTE is
transmitting, the signal will only be present at the receiver outputs
RX+ and RX if it appears on the coaxial cable and is larger than
the receiver squelch threshold V

. If a short circuit fault condition

occurs at the cable connector to the CTI, then no signal will appear
at the receiver outputs.

In the case of an open circuit at the coaxial cable connector there
will also be no signal at the receiver outputs due to the AUI disabling
mode of the NE83Q92. However, a heartbeat signal will be present
following a transmission attempt for the short circuit condition, but
not for the open circuit.

A coaxial cable with only a single 50

termination will generate a

collision not only at every transmission attempt, but also for every
reception attempt due to the receive mode collision detection of the
NE83Q92.

CD+

CD

RX+

VEE

RX

TX+

TX

HBE

GND

RR+

VEE

RXI

TXO

CDS

RR

500

9V (ISOLATED)

DC TO DC

CONVERTER

<200mA

TRANSMIT

PAIR

RECEIVE

PAIR

COLLISION

PAIR

12 TO 15V DC

(NOTE 2)

NOTES:
1. T1 is a 1:1 pulse transformer, with an inductance of 30 to 100

2. IN916 or equivalent for Ethernet, not required for Thin Ethernet.
3. 78

resistors not required if AUI cable not present.

4. Not required for optimal integrated/local MAU application (No AUI cable, see Note 3), minimum current consumption.
5. Install 200k

to disable the 400ms collision announcement when disconnecting cable.

NE83C92

CTI

T1 (NOTE 1)

COAX

DTE

AUI

CABLE

(NOTE 3)

SD00309

(NOTE 4)

200k

(NOTE 5)

Figure 1. Connection Diagram for Standard 8392 Applications

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