HYC9088A
Half Height
ARCNET Twisted Pair and Coaxial Compatible
High Impedance Transceiver HIT
FEATURES
•ARCNET on Twisted Pair or Coaxial Cable
•Drives Shielded and Unshielded Twisted Pair
Cable or Coaxial Cable
•Compatible with Existing ARCNET
Installations
•2.5 Mbps operation
•Pin Compatible with the ARCNET HYC9068
LAN Driver with the Addition of a Single
Terminating Resistor
•Supports Star, Bus, and Daisy Chained
Configurations
•Enhanced Built-in Filters for Reduced EMI
•Twenty Pin Single In-Line Package
•Straight or Right Angle Lead Frame
•New Reduced Size
GENERAL DESCRIPTION
The HYC9088 Twisted Pair and Coaxial
Compatible High Impedance Transceiver (HIT)
is a hybrid module that interfaces an ARCNET
Local Area Network controller to one twisted pair
or coaxial cable. The HIT interfaces directly
with Standard Microsystems Corporation's
ARCNET LAN controllers operating at 2.5 Mbps
and connects to a variety of shielded and
unshielded twisted pair or coaxial cables via an
on-board transformer. The network topologies
supported by the HIT are daisy chain, star, and
bus configurations.
During data transmission, the HIT converts the
digital pulse information provided by the LAN
controller into analog signals and drives them
onto the cable. The transmitted signals are
filtered to eliminate undesirable frequencies. The
receiver section of the HYC9088 identifies
dipulse signals on the cable and converts them
into TTL signals to be supplied to the LAN
controller.
The HIT supports ARCNET's Dipulse Encoding
Scheme and, is 100% compatible with all
existing coax-based ARCNET networks. This
provides an ARCNET network designer with
flexibility to easily combine coax and twisted
pair cabling.
The HYC9088 is pin compatible with the
HYC9058 High Impedance Transceiver and is
pin compatible with the HYC9068 LAN Driver
with the addition of a single terminating resistor.
ARCNET is a registered trademark of Datapoint Corporation.
HIT is a trademark of Standard Microsystems Corporation.
2
TABLE OF CONTENTS
FEATURES........................................................................................................................................1
GENERAL DESCRIPTION..................................................................................................................1
PIN CONFIGURATION.......................................................................................................................3
DESCRIPTION OF PIN FUNCTIONS ................................................................................................ 4
FUNCTIONAL DESCRIPTION............................................................................................................5
APPLICATION INFORMATION.......................................................................................................... 5
OPERATIONAL DESCRIPTION....................................................................................................... 11
MAXIMUM GUARANTEED RATINGS................................................................................11
DC ELECTRICAL CHARACTERISTICS ............................................................................ 11
80 Arkay Drive
Hauppauge, NY 11788
(516) 435-6000
FAX (516) 273-3123
3
PIN CONFIGURATION
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
NC
NC
VDD
GND
NC
VCC
RX
TPA
NC
TPD
PH-B/SHIELD
PH-A/CENTER
GND
GND
TPC
TPB
GND
nPULSE2
DISABLE
nPULSE1
PACKAGE: 20-Pin SIP
Ordering Information:
HYC9088AR for right angle lead frame
HYC9088AS for straight lead frame
T
O
P
V
I
E
W
Pin 1 Designator
4
DESCRIPTION OF PIN FUNCTIONS
PIN NO. NAME SYMBOL DESCRIPTION
1, 2, 5, 9 No Connect NC Not used. Make no connection to these pins.
3Power
Supply VDD -5 Volts power supply.
4, 13, 14,
17 Ground GND Ground.
6Power
Supply VCC +5 Volts power supply.
7Receive
Data RX Output. This signal carries the TTL receive pulse
information to the ARCNET LAN Controller Device.
8, 16, 15,
10 Test Points TPA, TPB,
TPC, TPD Test points. Make no connection to these pins.
11 Phase-B/
Shield PH-B/
SHIELD Output. Connect this signal to Twisted Pair Connector pin 3
or the shield of the coaxial cable.
12 Phase-A/
Center PH-A/
CENTER Output. Connect this signal to Twisted Pair Connector pin 2
or the center of the coaxial cable.
18 nPulse 2 nPULSE2 Input. This signal is supplied by the ARCNET LAN
Controller Device.
19 Disable TX DISABLE
TRANSMIT Input. A high level on this signal disables the transmit
section of the HYC9088. It is normally connected to
ground.
20 nPulse 1 nPULSE1 Input. This signal is supplied by the ARCNET LAN
Controller Device.
5
FUNCTIONAL DESCRIPTION
The HIT integrates a host of discrete
components into a hybrid module and provides
the Local Area Network designer with space and
cost savings as well as the enhanced reliability
of a single component. Since the HIT is a high
impedance transceiver, it does not disturb the
characteristic impedance of the cable used to
interconnect ARCNET nodes. The two far ends
of the twisted pair cable must be terminated
using terminating resistors equal to the
characteristic impedance of the cable. The HIT
is made up of a transmit section and a receive
section. (Please refer to Figure 1).
Transmit Section
The ARCNET LAN controller transmits a logic
"1" by generating two 100 ns non-overlapping
negative pulses, nPULSE1 and nPULSE2.
These signals are converted by the HIT into a
200 ns dipulse signal. The HIT shapes the 200
ns signal into a single cycle of a 5 MHz sine-
wave and filters higher frequency components.
The dipulse signal is then transformer-coupled
onto the cable and has a minimum voltage
output of 16 Volts peak-to-peak. The exact
output voltage of the HIT will vary depending on
the characteristic impedance of the cable used.
The driving circuitry of the HIT has been
designed to present a high impedance on the
cable in order to minimize loading.
The DISABLE input of the HYC9088 can be
used to prevent the device from transmitting.
During normal operation, the DISABLE input is
tied to ground.
Receiver Section
The received dipulse signal from the cable is
electrically isolated through the use of a
transformer. This signal is passed through a
filter which eliminates out of band noise. The
receive signal is then fed to a comparator which
converts it into a TTL signal ready to be applied
to the LAN controller chip. The comparator
compares the received signal to an internal
voltage threshold to distinguish noise from real
signal.
APPLICATION INFORMATION
Small Twisted Pair Networks
The HIT eliminates the need for active hubs in
small ARCNET networks. For example, a ten
node ARCNET network can be constructed by
connecting ten HITs using a daisy-chained or
bus configuration (see Figure 2). Note that both
extremes of the cable must be terminated with a
resistor which matches the characteristic
impedence of the Twisted Pair Cable. For the
cable types specified in Table 1, the maximum
length of the twisted pair cable recommended is
400 feet.
Small Coax Network
No active hub is required for an ARCNET
network consisting of eight nodes or less using
the HYC9088 for coax cable (See Figure 2A).
Both ends of the cable must be terminated with
a resistor which matches the characteristic
impedance of the coax cable. For the RG62
cable specified in Table 1, the maximum length
of the coax cable recommended is 1000 feet.
6
Combination of Twisted Pair and Coax
Networks
A Two-Port Link is used to combine twisted pair
network and a coax network. A Two-Port Link
has a coax connector on one side and two
modular jacks on the other and contains the
proper impedance-matching circuitry. Refer to
Figure 3 for an illustration of a twisted pair
network combined with a coaxial network.
Proper Connection for Twisted Pair
Each twisted pair compatible ARCNET node
would typically have two RJ-11 modular
connectors mounted on the node card (refer to
Figure 4). PHASE A should be connected to pin
2 of the connectors and PHASE B to pin 3. A
twisted pair segment would have an RJ-11
modular jack on each end (see Figure 5). Please
note that the suggested numbering scheme of
the modular jack shown in Figure 5 may not be
consistent with that found on some
manufacturers' products. Please ensure
consistent connection of Phase A and Phase B
signals throughout the network to avoid the
reception of erroneous data.
Table 1 - Specifications for Cabling
PARAMETER VALUE FOR COAX VALUE FOR TWISTED PAIR
Wiring RG62 Solid Copper 22, 24, or 26 AWG
Number of Twists/Foot N/A 2 min.
DC Resistance 3.4 Ohms/1000 ft. 28.6 Ohms/1000 ft. max.
Characteristic Impedance 93 Ohms at 1 MHz 105 Ohms 20% at 1 MHz
Maximum Attenuation 5.5 dB/1000 ft. at 5 MHz 16.0 dB/1000 ft. at 5 MHz
7
FIGURE 1 – HYC9088 INTERNAL BLOCK DIAGRAM
FIGURE 2 – TYPICAL SMALL TWISTED PAIR ARCNET NETWORK USING HYC9088A
FILTER
ISOLATION
TRANSFORMER
DISABLE
19
nPULSE 1 20
18
nPULSE 2
Rx
DATA
7
6 4 3 13 14 17
+5V GND -5V GND GND GND
TPA
TPB
TPC
TPD
8
16
15
10
11 PH-B/SHIELD
12 PH-A/CENTER
NC
NC
NC
1
2
9
FILTER,
AMPLIFIER
AND
DIFFERENTIAL
DRIVER
VOLTAGE
THRESHOLD
DETECTOR
NC
5
400 FEET MAXIMUM
1 32 10
TT
6 FEET
MINIMUM
8
FIGURE 2A – TYPICAL SMALL COAX ARCNET NETWORK USING HYC9088A
FIGURE 3 – TYPICAL COMBINATION OF TWISTED PAIR AND COAXIAL CABLE ON AN
ARCNET NETWORK USING HYC9088A
T T
T
1 2 3 9
TWO-
PORT
LINK
10TH CONNECTION
8TH CONNECTION
400 FEET MAXIMUM
TWISTED PAIR CABLE
6 FEET
MINIMUM
1000 FEET MAXIMUM
*For more detail, see TN 7-1
**Stub length should be kept as short as possible
T
1 2 3 7
COAXIAL CABLE*
3 FEET
MINIMUM
d**
1000 FEET MAXIMUM
T
1 2 3 8
3 FEET
MINIMUM T
9
FIGURE 4 – RJ-11 CONNECTORS ON NODE CARD
FIGURE 5 – PHASE RELATIONSHIP ON TWISTED PAIR SEGMENT AND RJ-11
CONNECTOR PINOUT
ARCNET NODE
4-Lead Modular Plugs
1 2 3 4
1 2 3 4
4 3 2 1*
4 3 2 1*
*
32
32
*
*Please note that the numbering scheme of the modular jack shown above is the
opposite of that found onStandard Microsystems'Systems Products Division's boards
and hubs. Please adhere to one scheme and ensure consistent connection of Phase
A and Phase B signals throughout the network for proper operation.
10
FIGURE 6 – TYPICAL HYC9088A INTERCONNECT FOR TWISTED PAIR CABLE
FIGURE 7 – TYPICAL HYC9088A INTERCONNECT FOR COAXIAL CABLE
FIGURE 8 – DESCRIPTION OF TERMINATOR WIRING
1 2 3 4
1 2 3 4
J1*
J2*
27
pF
27
pF
5.6K
1/2W
5.6K
1/2W
5.6K
1/2W
5.6K
1/2W
12
11
PHASE
A/CENTER
PHASE
B/SHIELD
0.47
pF +
10
uF
0.47
pF
+
10
uF
3
+5V
-5V
6
nPULSE1
nPULSE2
RX
4,13,14
17,19
nPULSE1
nPULSE2
RXIN
GND
ARCNET
CONTROLLER/
TRANSCEIVER
HYC9088A
*Please see note in Figure 5 regarding the numbering scheme of the modular jack.
0.01
uF
5.6K
1/2W
5.6K
1/2W
12
11
PHASE
A/CENTER
PHASE
B/SHIELD
0.47
pF +
10
uF
0.47
pF
+
10
uF
3
+5V
-5V
6
nPULSE1
nPULSE2
RX
4,13,14
17,19
nPULSE1
nPULSE2
RXIN
GND
ARCNET
CONTROLLER/
TRANSCEIVER
HYC9088A
1KV
12
11
PHASE
A/CENTER
PHASE
B/SHIELD
COAXIAL CABLE
12
11
PHASE
A/CENTER
PHASE
B/SHIELD
TWISTED PAIR CABLE
TO RJ
11 RL
RL
11
OPERATIONAL DESCRIPTION
MAXIMUM GUARANTEED RATINGS*
Operating Temperature Range......................................................................................... 0oC to +70oC
Storage Temperature Range..........................................................................................-55o to +150oC
Lead Temperature Range (soldering, 10 seconds) ....................................................................+325oC
Positive Voltage on any pin, with respect to Ground................................................................Vcc+0.3V
Negative Voltage on any pin, except VDD, with respect to Ground.................................................-0.3V
*Stresses above those listed above could cause permanent damage to the device. This is a stress
rating only and functional operation of the device at any other condition above those indicated in the
operation sections of this specification is not implied.
Note: When powering this device from laboratory or system power supplies, it is important that the
Absolute Maximum Ratings not be exceeded or device failure can result. Some power supplies exhibit
voltage spikes on their outputs when the AC power is switched on or off. In addition, voltage
transients on the AC power line may appear on the DC output. If this possibility exists, it is suggested
that a clamp circuit be used.
DC ELECTRICAL CHARACTERISTICS (TA = 0oC to 70oC, VCC2 = +5.0 V ± 5%, VDD = -5.0V ± 5%)
PARAMETER SYMBOL MIN TYP MAX UNITS COMMENTS
Low Input Voltage
High Input Voltage
Received Signal Amplitude
VIL
VIH
VR
2.0
6.0
3.0
0.8 V
V
Vp-p
Vo-p
IIL = -0.8 mA
IIH = +0.2 mA
Low Output Voltage
High Output Voltage
Transformer Output
Cable Noise Amplitude
VOL
VOH
VT
VC
2.4
16
820
10
0.4
4
V
V
Vp-p
VO-p
Vp-p
One TTL Load
One TTL Load
Zchr cable = 120Ω
or 93Ω
VCC Supply Current
VDD Supply Current
ICC
IDD
190
180
285
270
mA
mA
Pulse Width, nPulse 1, n2 PW 100 nS
Shorting the transformer output may cause permanent damage to the device.
FIGURE 9 – 20 PIN SIP PACKAGE DIMENSIONS
STANDARD MICROSYSTEMS CORP. Circuit diagrams utilizing SMSC products are included as a means of illustrating typical
applications; consequently complete information sufficient for construction purposes is
not necessarily given. The information has been carefully checked and is believed to be
entirely reliable. However, no responsibility is assumed for inaccuracies. Furthermore,
such information does not convey to the purchaser of the semiconductor devices
described any licenses under the patent rights of SMSC or others. SMSC reserves the
right to make changes at any time in order to improve design and supply the best
product possible. SMSC products are not designed, intended, authorized or warranted
for use in any life support or other applications where product failure could cause or
contribute to personal injury or severe property damage. Any and all such uses without
prior written approval of an Officer of SMSC and further testing and/or modification will
be fully at the risk of the customer. HYC9088A Rev. 6/15/94
MIN
2.000
0.625
0.055
0.018
0.120
0.070
TYP
0.100
0.010
0.180
MAX
2.100
0.650
0.095
0.022
0.135
0.400
0.085
0.020
HYC9088AR for Right Angle Lead Frame
HYC9088AS for Straight Lead Frame
HYC9088AR
E
1
GC
A
D
B
SEATING PLANE F
H
SEATING PLANE
I
JK
90°-105°
DIM
A
B
C
D
E
F
G
H
I
J
K
NOTE: Dimensions are in inches
HYC9088AS
HYC9088A
H
G
