MTD392 View Datasheet(PDF) - Myson Century Inc
Part Name
Description
Manufacturer
MTD392 Datasheet PDF : 10 Pages
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MYSON
TECHNOLOGY
MTD392
FAMILY
RXI
I 14
CDS
I 16
RX+,RX- O
3
6
CD+,CD- O
1
2
TXO O 15
GND
10
VEE
4
5
13
COL, O
JAB,
XMT,
RCV,
TST- I
MOD- I
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.
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 400W
resistor should be connected from CDS to GND.
3
3 Receiving Data Output. A balanced differential output drives
6
6 data recovered from the network to the MCC. These outputs
are also open sources, and pull-down resistors from 510W 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.
1
1 Collision Output. A balanced differential line driver drives
2
2 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 510W 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.
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).
4
4 Positive Supply Pin (Ground). Should be connected to the
16
16 COAX shield.
17
17
5
5 Negative Power Supply. -9 volts. A 0.1mF decoupling
20
20 capacitor must be connected across GND and VEE as close
21
21 to the device as possible.
7 Transceiver Status Indicators. LED displays for collision,
8 jabber, transmission and reception. These pins are open-
11 drain output buffers that are used to drive LED status
12 indicators. They are designed to supply 8 mA sinking
capability.
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 50kW internal pull-up resistor.
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
MTD392 Revision 2.01 02/25/1997
5/10
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