MYSON
TECHNOLOGY
MTD392
FAMILY
Coaxial Transceiver Interface
This datasheet contains new product information. Myson Technology reserves the rights to modify the product specification without notice.
No liability is assumed as a result of the use of this product. No rights under any patent accompany the sale of the product.
MTD392 Revision 2.01 02/25/1997
1/10
FEATURES
Compatible with ISO/IEEE 802.3 10Base5 (Ethernet) and 10Base2 (Cheapernet).
Functionally compatible with National DP8392C.
Internal squelch circuitry for noise rejection.
Reception/transmission mode collision detection.
Transceiver functions integrated except for signal and power isolation.
CD heartbeat externally selectable.
Advanced low-power, high-performance CMOS technology.
ESD protection greater than 2000 volts.
16-pin plastic DIP package, 24-pin skinny plastic DIP package, or 20 and 28-pin PLCC packages.
Built-in LED drivers for collision, reception, jabber and transmission status display
(MTDX93/X94 only).
Collision detection mode for reception, transmission and hybrid
(MTDX94 only).
Special test mode allowing continuous transmission for waveform testing
(MTDX94 only).
GENERAL DESCRIPTION
The MTD392 family includes a series of products, MTD392/3/4 and MTD492/3/4. The MTD392 product family
is built for easy MAU interface in a coaxial Ethernet network. The MTD392 product family integrates the coaxial
cable interface functions of Medium Attachment Unit (MAU) in Ethernet or Cheapernet LAN applications. In an
Ethernet 10Base5 network, the MTD392 product family is mounted on the thick Ethernet coaxial cable and
connects to a station through an AUI cable. For Cheapernet applications, the MTD392 product family is
connected to the Cheapernet coaxial cable through a BNC connector and is usually mounted on the LAN
adapter in a station.
Following is a table describing the differences among the MTD392 product family:
Product
Features
Package
Types
Recommended Applications
MTD392
Basic transceiver
16-PDIP
28-PLCC
Adapter boards
MTD393
MTD392 with built-in LEDs
20-PLCC
24-PDIP
Adapter cards with status LEDs
MTD394
MTD393 with enhanced collision
detection mode, special pin for
testing
24-PDIP
28-PLCC
MTD393 applications with enhanced
collision detection
MTD49X
MTD39X with improved
performance
Basic MTD39X applications, Hub,
repeater and MAU applications
MYSON
TECHNOLOGY
MTD392
FAMILY
MTD392 Revision 2.01 02/25/1997
2/10
BLOCK DIAGRAM FOR MTD392 FAMILY
HIGH PASS
EQUALIZATION
LOW PASS
FILTER
LOW PASS
FILTER
COM
-
+
LOW PASS
FILTER
125
10K
REFERENCE
CIRCUIT
1K
AUI
DRIVER
AUI
DRIVER
CARRIER
SENSE
-
+
WAVEFORM
SHAPING
+
-
DC/AC
SQUELCH
WATCH DOG
TIMER 26ms
JABBER RESET
TIMER 0.4sec
10MHz
OSC
TRANSMIT
STATE
MACHINE
RECEIVE
STATE
MACHINE
XMTSQ
CLK
VEE
COLLISION
HBE
FXI
GND
COAX
VEE
XMT
CDS
RECV
TXO
RR+
RR-
RX+
RX-
CD+
CD-
TX+
TX-
Block Diagram for MTDX92
HIGH PASS
EQUALIZATION
LOW PASS
FILTER
LOW PASS
FILTER
COM
-
+
LOW PASS
FILTER
125
10K
REFERENCE
CIRCUIT
1K
AUI
DRIVER
AUI
DRIVER
CARRIER
SENSE
-
+
WAVEFORM
SHAPING
+
-
DC/AC
SQUELCH
WATCH DOG
TIMER 26ms
JABBER RESET
TIMER 0.4sec
10MHz
OSC
TRANSMIT
STATE
MACHINE
RECEIVE
STATE
MACHINE
XMTSQ
CLK
VEE
COLLISION
HBE
FXI
GND
COAX
VEE
XMT
CDS
RECV
TXO
RR+
RR-
RX+
RX-
CD+
CD-
TX+
TX-
JAB
XMT
COL
RCV
Block Diagram for MTDX93
MYSON
TECHNOLOGY
MTD392
FAMILY
MTD392 Revision 2.01 02/25/1997
3/10
HIGH PASS
EQUALIZATION
LOW PASS
FILTER
LOW PASS
FILTER
COM
-
+
LOW PASS
FILTER
125
10K
REFERENCE
CIRCUIT
1K
AUI
DRIVER
AUI
DRIVER
CARRIER
SENSE
-
+
WAVEFORM
SHAPING
+
-
DC/AC
SQUELCH
WATCH DOG
TIMER 26ms
JABBER RESET
TIMER 0.4sec
10MHz
OSC
TRANSMIT
STATE
MACHINE
RECEIVE
STATE
MACHINE
XMTSQ
CLK
16X
COLLISION
HBE
FXI
GND
COAX
VEE
XMT
CDS
RECV
TXO
RR+
RR-
RX+
RX-
CD+
CD-
TX+
TX-
JAB
XMT
COL
RCV
1X
MODE
CLK/1024
TEST
TEST
MOD
LED DRIVER
Block Diagram for MTDX94
1.0 CONNECTION DIAGRAM
(1) MTDX92 Pin Diagram
MTD392N
16 PIN PDIP
MTD392V
28 PIN PLCC
CD+
CD-
RX+
VEE
VEE
RX-
TX+
TX-
CDS
TX0
RXI
VEE
RR-
RR+
GND
HBE
VEE
VEE
VEE
VEE
VEE(NC)
VEE(NC)
VEE(NC)
RX+
CD-
CD+
CDS
TXD
NC
RXI
VEE(NC)
VEE
VEE
VEE
VEE
VEE(NC)
RR-
RX-
TX+
TX-
HBE
GND
GND
RR+
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
MYSON
TECHNOLOGY
MTD392
FAMILY
MTD392 Revision 2.01 02/25/1997
4/10
(2) MTDX93 Pin Diagram
MTD393N
24 PIN PDIP
(300 MIL)
CD+
CD-
RX+
GND
VEE
RX-
COL
JAB
TX+
TX-
XMT
RCV
CDS
TX0
RXI
VEE
VEE
RR-
RR+
GND
GND
NC
NC
HBE
1
2
3
4
5
6
7
8
9
10
11
12
24
23
22
21
20
19
18
17
16
15
14
13
MTD393V
20 PIN PLCC
GND
VEE
RX-
COL
JAB
RX+
CD-
CD+
CDS
TXO
RXI
VEE
RR-
RR+
GND
TX+
TX-
XMT
RCV
HBE
(3) MTDX94 Pin Diagram
MTD394N
24 PIN PDIP
(300 MIL)
CD+
CD-
RX+
GND
VEE
RX-
COL
JAB
TX+
TX-
XMT
RCV
CDS
TX0
RXI
VEE
VEE
RR-
RR+
GND
GND
MOD~
TST~
HBE
1
2
3
4
5
6
7
8
9
10
11
12
24
23
22
21
20
19
18
17
16
15
14
13
MTD394V
28 PIN PLCC
RX+
GND
VEE
RX-
COL
JAB
TX+
GND
GND
CD-
CD+
GND
CDS
TXD
RXI
VEE
VEE
VEE
RR-
RR+
GND
TX-
XMT
RCV
HBE
TST
MOD
GND
2.0 PIN DESCRIPTIONS
Name
I/O
MTD
X92
PIN#
MTD
X93
PIN#
MTD
X94
PIN#
Description
TX+,TX-
I
7
8
9
10
9
10
Transmission Data Input. A balanced differential line
receiver that receives input from the off-chip Manchester
Code Converter (MCC) to the Transmitter. The common
mode voltage on TX
is set internally.
HBE
I
9
13
13
Heartbeat Enabler. The CD heartbeat test is enabled when
HBE is connected to Ground and disabled when HBE is
connected to VEE.
RR+,RR-
I
11
12
18
19
18
19
External Resistor. A 1k
W,/1% resistor should be connected
across these pins to correctly set internal operating currents.
RR+ is internally shorted to GND.
MYSON
TECHNOLOGY
MTD392
FAMILY
MTD392 Revision 2.01 02/25/1997
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RXI
I
14
22
22
Network Receiving Input. Should be connected to the
COAX center conductor. Signals meeting receiver squelch
limits are recovered and output on RX
/RXI also detects the
collision voltage level.
CDS
I
16
24
24
Collision Detecting Sense. Connects directly to the COAX
shield, providing a reference for the collision detection voltage
level for receiving-mode detection. An external bias network
can be used to shift the detection threshold for transmission-
detection mode. For hybrid mode collision detection, a 400
W
resistor should be connected from CDS to GND.
RX+,RX-
O
3
6
3
6
3
6
Receiving Data Output. A balanced differential output drives
data recovered from the network to the MCC. These outputs
are also open sources, and pull-down resistors from 510
W to
VEE are required. To minimize power dissipation, both open
source outputs are disabled during idle conditions, allowing
the common mode on the pull-down resistor to be pulled to
VEE.
CD+,CD-
O
1
2
1
2
1
2
Collision Output. A balanced differential line driver drives
this output pair from the collision detection circuitry. A 10MHz
signal from the internal oscillator is transferred to these
outputs in the event of collision or excessive transmission
(jabber), or during heartbeat condition. These outputs are
open sources, and pull-down resistors from 510
W to VEE are
required. To minimize power dissipation, both open source
outputs are disabled during idle condition, allowing the
common mode on the pull-down resistors to be pulled to VEE.
TXO
O
15
23
23
Transmitter Output. Should be connected to the coaxial
cable via one serial isolation diode for Cheapernet/Thinnet (10
Base2) or 2 serial isolation diodes for Thicknet (10 Base5).
GND
10
4
16
17
4
16
17
Positive Supply Pin (Ground). Should be connected to the
COAX shield.
VEE
4
5
13
5
20
21
5
20
21
Negative Power Supply. -9 volts. A 0.1
mF decoupling
capacitor must be connected across GND and VEE as close
to the device as possible.
COL,
JAB,
XMT,
RCV,
O
7
8
11
12
Transceiver Status Indicators. LED displays for collision,
jabber, transmission and reception. These pins are open-
drain output buffers that are used to drive LED status
indicators. They are designed to supply 8 mA sinking
capability.
TST-
I
14
Test Enabler. When both TST- and MOD- pins are shorted to
VEE, MTDX94 enters into test mode. In this mode, the jabber
function is disabled and all state timing is accelerated by 1024
times. This pin has a 50k
W internal pull-up resistor.
MOD-
I
15
Mode Selection. Along with the TST- pin, determines the
collision detection method of MTDX94. If both MOD- and
TST- are connected to GND, MTDX94 implements receiving-
mode collision detection. The typical detection threshold in
receiving-mode is -1.53V. To implement transmission-mode
collision detection, the detection threshold can be lowered by
placing a resistor bias network on the CDS pin. When the
TST- pin is connected to GND and the MOD- pin is connected
to VEE, MTDX94 uses hybrid-mode for collision detection. In
this mode, the threshold is set at -0.42V during idle or
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