PHILIPS NE83C92A

Philips Semiconductors
Product specification
Low-power coaxial Ethernet transceiver
DESCRIPTION
NE83C92
PIN CONFIGURATION
The NE83C92 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 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. Power isolation for the
CTI is achieved using DC-to-DC conversion through a power
transformer.
N Packages
CD–
2
15 TXO
3
14
VEE
4
13 VEE
VEE
5
12 RR–
RX–
6
11 RR+
TX+
7
10 GND
TX–
8
9
RXI
HBE
2
1
RXI
3
N/C
CD+
CDS
4
TXO
RX+
CD–
A PACKAGE
The NE83C92 is manufactured on an advanced BiCMOS process
and is available with PLCC package 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 application.
28 27 26
V
EE 5
V
EE 6
V
EE 7
V
EE 8
V
EE 9
V
EE 10
V
EE 11
20
19
RX–
reduces external part count (local/integrated MAU requires no
external pull-down resistors).
TX+
12 13
RR–
14 15 16 17 18
RR+
• Optimal implementation can use 1 Watt DC-DC converter and
V
EE
V
EE
V
EE
V
EE
V
EE
21
GND
industry standard 8392 sockets
VEE
24
22
GND
10BASE-2, and ISO 8802/3 interface specifications
TX–
• Fully compliant with Ethernet II, IEEE 802.3 10BASE-5 and
25
23
HBE
FEATURES
• 100% drop-in compatible with
1
RX+
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
automatic selection between AUI and coaxial connections, and
requires no external pull-down resistors for local integrated MAU
application.
16 CDS
CD+
• High efficiency AUI drivers automatically power-down under idle
SD00308
conditions to minimize current consumption
• Available in 16-pin DIP, and 28-pin PLCC packages
• Expanded version (NE83Q93) with 5 LED status drivers is
• Automatically disabling AUI drivers when disconnecting coax
cable, allowing hardwiring of AUI connection and local/integrated
CTI connection
available for repeater and advanced system applications
• Full ESD protection
• Power-on reset prevents glitches on coaxial cable during
• Smart squelch on data inputs eliminates false activations
• Advanced BiCMOS process for extremely low power operation
power-up
ORDERING INFORMATION
TEMPERATURE RANGE
ORDER CODE
DWG #
16-Pin Plastic Dual In-Line Package
DESCRIPTION
0 to +70°C
NE83C92N
SOT28-4
28-Pin Plastic Leaded Chip Carrier
0 to +70°C
NE83C92A
SOT261-3
1995 May 1
1
853-1736 15180
Philips Semiconductors
Product specification
Low-power coaxial Ethernet transceiver
NE83C92
PIN DESCRIPTIONS
PIN NO.
N PKG
PIN NO.
PLCC
SYMBOL
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 with
local/integrated MAU application.
3
6
4
12
RX+
RX–
Receiver Outputs. Balanced differential line driver outputs which send the received signal to the DTE.
External pull-down resistors are optional with local/integrated MAU application.
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.
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 connected directly to the coaxial cable shield for standard Ethernet operation.
10
16
17
GND
Positive Supply Pin.
4
5
13
5 to 11
20 to 25
VEE
DESCRIPTION
Negative Supply Pins.
NOTE:
1. The IEEE 802.3 name for CD is CI; for RX is DI; for TX is DO.
1995 May 1
2
Philips Semiconductors
Product specification
Low-power coaxial Ethernet transceiver
NE83C92
BLOCK DIAGRAM
DTE
INTERFACE
COAX
CABLE
RXI
BUFFER
LINE
DRIVER
RECEIVE
PAIR
(RX+, RX–)
RECEIVER
EQUALIZER
4–POLE BESSEL
LOW PASS FILTER
RECEIVER
AC–DC SQUELCH
TXO
TRANSMIT
PAIR
(TX+, TX–)
TRANSMITTER
CDS
SENSE
BUFFER
TRANSMITTER
SQUELCH
COLLISION
COMPARATOR
&
HEARTBEAT
GENERATOR
HEARTBEAT ENABLE
COLLISION
PAIR
(CD+, CD–)
10MHz
OSC
JABBER
TIMER
LINE
DRIVER
SD00274
ABSOLUTE MAXIMUM RATINGS
SYMBOL
PARAMETER
voltage1
VEE
Supply
VIN
Voltage at any input1
TSTG
Storage temperature range
TSOLD
RATING
UNIT
–12
V
0 to –12
V
–65 to +150
°C
Lead soldering temperature (10sec.)
+300
°C
TJ
Recommended max junction temperature2
+150
°C
θJA
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:
TJ = TA + θJA [(VEE x 0.015 x nIDL) + (VEE x 0.018 x nRX) + (VEE x 0.066 x nTX)]
where
TA = Ambient temperature in °C.
θJA = Thermal resistance of package.
VEE = Normal operating supply voltage in volts.
nIDL = Percentage of duty cycle idle
nRX = Percentage of duty cycle receiving
nTX = Percentage of duty cycle transmitting
1995 May 1
3
Philips Semiconductors
Product specification
Low-power coaxial Ethernet transceiver
NE83C92
ELECTRICAL CHARACTERISTICS
VEE = –9V ±6%; TA = 0°C to +70°C unless otherwise specified1,2. No external isolation
LIMITS
SYMBOL
VUVL
IEE
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
Under voltage lockout. Transceiver disabled for
|VEE| < |VUVL|
–7.5
Supply current idle
–15
–20
mA
–70
–85
mA
+25
µA
+3
µA
Supply current transmitting (without collision)
Without external
pull-down resistors
IRXI
Receive input bias current
VRXI = 0V
ICDS
Cable sense input bias current
VCDS = 0V
VIH
HBE input HIGH voltage
VIL
HBE input LOW voltage
IIH
HBE input HIGH current
VHBE = 0V
IIL
HBE input LOW current
VHBE = VEE
–2
+1
V
VEE +2.4
V
VEE +1.6
V
+10
µA
µA
–30
ITDC
Transmit output DC current level3
–37
–45
mA
ITAC
Transmit output AC current level3
±28
±ITDC
mA
ITX10
Transmit current
–250
+250
µA
–3.7
V
–1580
mV
VTCOM
VTXO = –10V
Transmitter output voltage compliance4
Measured by applying
DC voltage at RXI
(CDS = 0V)
VCD
Collision threshold5
VDIS
AUI disable voltage at RXI
VOD
Differential output voltage – non idle at RX+ and
CD±6
VOB
Differential output voltage imbalance – idle at
RX± and CD±7
VOC
Output common mode voltage at RX± and CD±
VRS
Receiver squelch threshold
VTS
Transmitter squelch threshold
RRXI
Shunt resistance at RXI non–transmitting
–1450
Measured as DC
voltage at RXI
–1530
–3.5
±600
V
±1100
mV
±40
mV
RXI = 0V
–4.0
–5.5
–7.0
V
VRXI average DC
(CDS = 0V)
–150
–250
–350
mV
(VTX+ – VTX–) peak
–175
–225
–275
mV
100
RXI8
kΩ
CRXI
Input capacitance at
RTXO
Shunt resistance at TXO transmitting
10
kΩ
RAUIZ
Differential impedance at RX± and CD± with no
coaxial cable connected
6
kΩ
Differential impedance at TX±
20
kΩ
RTX
1
7.5
2
pF
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 typicals are for VEE = –9V and TA = 27°C.
3. ITDC is measured as (VMAX + VMIN)/(2 x 25) where VMAX and VMIN are the max and min voltages at TXO with a 25Ω load between TXO and
GND. ITAC is measured as (VMAX – VMIN)/(2 x 25).
4. The TXO pin shall continue to sink at least ITDC min when the idle (no signal) voltage on this pin is –3.7V.
5. Collision threshold for an AC signal is within 5% of VCD.
6. Measured on secondary side of isolation transformer. The transformer has a 1:1 turns ratio with an inductance between 30 and 100µH 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.
1995 May 1
4
Philips Semiconductors
Product specification
Low-power coaxial Ethernet transceiver
NE83C92
TIMING CHARACTERISTICS
VEE = –9V +6%; TA = 0 to 70°C, unless otherwise specified1. No external isolation diode on TXO.
LIMITS
SYMBOL
PARAMETER
TEST CONDITIONS
tRON
Receiver start up delay RXI to RX± (Figure 3)
First received bit on RX±
MIN
TYP
MAX
UNIT
VRXI = –2V peak
3
5
bits
tRON +2
bits
VRXI = –2V peak
20
50
ns
tRR
Differential output rise time on RX± and
CD±2,3
5
7
ns
tRF
Differential output fall time on RX± and CD±2,3
5
7
ns
tOS
Differential output settling time on RX± and CD±
to VOB = 40mV2 (see Figure 4)
1
First validly timed bit on RX±
tRD
Receiver prop. delay RXI to RX±
tRJ
Receiver and cable total jitter
tRHI
Receiver high to idle time
tRM
Rise and fall time matching on RX+ and CD+
tTST
Transmitter start-up delay TX± to TXO (Figure 5)
First transmitted bit on TXO
±2
Measured to +210mV
200
Transmitter prop delay TX± to TXO
(see Figure 5)
tTR
tTF
±6
ns
850
ns
tRF – tRR
0.1
±2
ns
VTX+ = –1V peak
1
2
bits
tTST + 2
bits
First validly timed bit
tTD
µs
VTX+ = 1V peak
5
20
50
ns
Transmitter rise time 10% to 90% (see Figure 5)
20
25
30
ns
Transmitter fall time 10% to 90% (see Figure 5)
20
25
30
ns
0
±2
ns
0
±2
ns
ns
mismatch5
tTM
tTF – tTR
tTS
Transmitter added skew4,5
tTON
Transmitter turn on pulse width (see Figure 5)
VTX± = 1V peak
10
35
tTOFF
Transmitter turn off pulse width (see Figure 5)
tCON
Collision turn on delay (see Figure 6)
0V to –2V step at RXI
VTX+ = 1V peak
125
200
ns
13
bits
tCOFF
Collision turn off delay (see Figure 6)
–2V to 0V step at RXI
tCHI
Collision high to idle time (see Figure 6)
Measured to +210mV
fCD
Collision frequency (see Figure 6)
tCP
200
8.5
10
16
bits
850
ns
11.5
MHz
Collision signal pulse width (see Figure 6)
35
70
ns
tHON
Heartbeat turn on delay (see Figure 7)
0.6
1.6
µs
tHW
Heartbeat test duration (see Figure 7)
0.5
1.5
µs
tJA
Jabber activation delay measured from TX± to
CD± (see Figure 8)
20
60
ms
tJR
Jabber reset delay measured from TX± to CD±
(see Figure 8)
250
650
ms
NOTES:
1. All typicals are for VEE = –9V and TA = 27°C.
2. Measured on secondary side of isolation transformer (see Figure 2). The transformer has a 1:1 turn ratio with an inductance between 30
and 100µH 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.
1995 May 1
5
Philips Semiconductors
Product specification
Low-power coaxial Ethernet transceiver
The differential line driver provides typically +900mV signals to the
DTE with less than 7ns rise and fall times. When in idle state (no
received signal) its outputs provide <20mV differential voltage offset
to minimize DC standing current in the isolation transformer.
FUNCTIONAL DESCRIPTION
The NE83C92 is a low power BiCMOS coaxial Ethernet transceiver
which complies with the IEEE 802.3 specification and offers the
following features:
Transmitter Functions
1. Low current consumption of typically 15mA when idling and
70mA while transmitting and no collision allows smaller DC-DC
converter to be used for the isolated power supply. (No external
pull-down resistors.)
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 NE83C92 meets the capacitive
loading specifications. For Ethernet applications a further external
diode should be added to reduce loading capacitance.
2. Automatic selection of the AUI connector (for remote MAU)
instead of the direct local (Thin) coaxial connection is possible by
automatically placing the AUI drivers in high-impedance state
when the local coaxial cable is disconnected. This eliminates the
need for changing a jumper position on the Ethernet board when
selecting either one of the connections. (Automatic selection of
the local (Thin) connection is done by disconnecting the AUI
cable and reconnecting the local coaxial one, which allows the
NE83Q92 to automatically activate itself.)
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.
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.
4. The NE83C92 advanced AUI driver (RX± and CD±) design does
require external pull-down resistors (500Ω) to drive a terminated
(78Ω) AUI cable. However, these drivers will operate correctly
without the external resistors for integrated/local MAU
applications where no AUI cable is used. Hence, they can be
retro-fitted into existing 8392 designs with or without external
pull-down resistors depending on the application. An extra
current of 7mA/output (for 500Ω resistors) would be generated,
by these resistors, regardless of whether the transceiver is idle
or responding to traffic.
Collision Functions
The collision detection scheme implemented in the NE83C92 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.
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 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.
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.
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 1µs burst of 10MHz
oscillation at the line driver outputs approximately 1µs after the end
of the transmission. The heartbeat function can be disabled
externally by connecting the HBE (heartbeat enable) to VEE. This
allows the CTI to be used in repeater applications. Figure 7
illustrates heartbeat timing.
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 .5µs. Figures 3 and 4 illustrate receiver timing.
1995 May 1
NE83C92
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.
6
Philips Semiconductors
Product specification
Low-power coaxial Ethernet transceiver
NE83C92
POR/Under Voltage Lockout/AUI Selection
Detection of Coaxial Cable Faults
The transmit and receive squelch circuits of the NE83C92 remain
active if the absolute value of VEE is less than the threshold for
under voltage lockout, VUVL. This prevents glitches from appearing
on either the AUI or coaxial cable during power up and power down.
In the NE83C92 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 VRS. If a short circuit fault condition
occurs at the cable connector to the CTI, then no signal will appear
at the receiver outputs.
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 VEE. If the absolute value of this voltage
exceeds the AUI disable voltage, VDIS, 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 10BASE-T transceiver, with the signal path determined by
which transceiver is connected to its external cable.
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 50Ω 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
NE83C92.
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 200kΩ to ground.
AUI
CABLE
12 TO 15V DC
+
DC TO DC
CONVERTER
<200mA
9V (ISOLATED)
–
500Ω
1
COLLISION
PAIR
500Ω
500Ω
78Ω
2
DTE
16
(NOTE 4)
500Ω
15
T1 (NOTE 1)
(NOTE 3)
COAX
4
13
CD+
RECEIVE
PAIR
78Ω
1
16
2
15
CD–
5
12
RX+
3
VEE
VEE
7
10
NE83C92
14
4
13
5
12
CTI
6
11
7
10
8
9
TX+
8
9
78Ω
TXO
VEE
GND
TX–
HBE
Figure 1. Connection Diagram for Standard 8392 Applications
7
200kΩ
RR+ 1kΩ 1%
NOTES:
1. T1 is a 1:1 pulse transformer, with an inductance of 30 to 100µH.
2. IN916 or equivalent for Ethernet, not required for Thin Ethernet.
3. 78Ω 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 200kΩ to disable the 400ms collision announcement when disconnecting cable.
1995 May 1
(NOTE 2)
RXI
RR–
RX–
TRANSMIT
PAIR
CDS
(NOTE 5)
SD00309
Philips Semiconductors
Product specification
Low-power coaxial Ethernet transceiver
NE83C92
MAU
COAX
I
S
O
L
A
T
I
O
N
NE83C92
COAX
TRANSCEIVER
INTERFACE
SERIAL
NETWORK
INTERFACE
(OPTIONAL)
(AUI CABLE)
NETWORK
INTERFACE
CONTROLLER
B
U
S
DTE
MAU = Medium Attachment Unit
AUI Cable = Attachment Unit Interface Cable (not used in Thin Ethernet applications)
SD00310
Figure 2. Interface Diagram for Ethernet/Thin Ethernet Local Area Network
RXI
1
2
3
4
PHASE VIOLATION
ALLOWED
5
6
VALID
TIMING
7
8
9
10
11
tRD
90%
RX+
10%
5
6
7
8
9
tRON+2
tTR
tRON
10
tTF
tRR
11
tRF
SD00306
Figure 3. Receiver Timing
RXI
tOS
tRHI
RX+
SD00279
Figure 4. Receiver End-of-Packet Timing
tTST+2
100ns
tTST
tTOFF
TX+
1
2
3
4
5
6
7
tTON
tTD
8
9
10
TXO
11
90%
10%
1
2
3
4
5
6
7
8
9
tTR
Figure 5. Transmitter Timing
1995 May 1
8
10 11
tTF
tRF
tRR
SD00305
Philips Semiconductors
Product specification
Low-power coaxial Ethernet transceiver
RXI
NE83C92
0V
–2V
tCON
tCOFF
tCHI
CD+
1/FCD
tCP
SD00280
Figure 6. Collision Timing
TX+
tHON
tHW
CD+
SD00281
Figure 7. Heartbeat Timing
TX+
tJA
tJR
TXO
CD+
SD00282
Figure 8. Jabber Timing
1995 May 1
9