AMD AM7996EVAL-HW

Advanced
Micro
Devices
Am7996EVAL-HW
Ethernet/Cheapernet Transceiver Evaluation Kit
DISTINCTIVE CHARACTERISTICS
■
Connects the standard AUI port interface to
10BASE–2 (Cheapernet) connector.
■
Jumper selectable Signal Quality Error (SQE)
test allows evaluation in both node and
repeater applications.
■
Self contained board facilitates rapid
evaluation of the AUI -to-coax system block,
and demonstrates optimal analog design
criteria.
GENERAL DESCRIPTION
The Am7996EVAL-HW board is a self contained module that implements all the functions of a Medium Attachment Unit (MAU) for IEEE 802.3 10BASE–2
(Cheapernet). This 3”x3” board can be used to connect
any AUI port interface to the ‘thin’ coaxial cable used in
Cheapernet networks. This system permits the network
designer to monitor signals on the card to increase his
understanding of IEEE 802.3 standards and conventions. A jumper selectable SQE test enable/disable lets
the board function in both user node or network repeater
applications. In addition, optimal PC board layout is employed. The Am7996EVAL-HW kit comes complete with
schematics, application notes, and coaxial cable connection hardware.
BLOCK DIAGRAM
AUI Port
Am7996
Cheapernet
DC – DC
Power
Supply
JUMPER SETTINGS
The jumper settings specify the type of collision detect
that is used.
Transmit collision detect:
connect 1 & 3
Receive collision detect:
connect 1 & 2
3&4
Publication# 14606
3–4
Rev. B
Issue Date: January 1992
Amendment/0
AMD
CIRCUIT DIAGRAM
1 VCC1
1
16
2 CI+
COLL OSC 19
Collision
2
15
3 CI–
A
VCOL 18
m
7
17
NC
9
9
6 RXT 16
P2-2
P2-9
4
P2-5
P2-12
VCC2 20
4
13
Receive
5
5
12
R8
PE64102
or
PE64107
7
10
Transmit
8
P2-10
9
174 1%
W2
SQE
DI–
NC
VCREF
R10
7 SQ
E
8 Test
DO+
R9
9 DO–
40.2 1%
P2-3
6
DI+
R4 5%
1.1 kΩ
33 pF
C5
RMC
TMC 1
3
4
499 Ω
R2
RMC
R1
150 kΩ
2
CL
24.9 kΩ
0.1 µF
C1
15
Tap 14
Shield
13 R7 9.09 1%
VTX–
C2
0.1 µF
P1
R5 75 K 1%
C3
BNC
Connector
C4
150 pF
CR2
CR1
IN4001 IN4150
TXT 12
R6 9.09 1%
40.2 1%
10 V
EE
VTX+ 11
–9 V
*DC – DC Converter
P2-13
+IN
C7
P2-6
P2-1
+4.7 µF
25 V
–OUT
C6
0.1 µF
+12 V
–IN
n/c
–9 V
C9
0.1 µF
C8
+4.7 µF
+OUT
C10
1500 pF
3 KV
P2-4
P2-8
P2-11
P2-14
Notes:
CL
= Effective Parasitic Capacitance
C3
= 1/3 CL (PC Trace was Used for C3)
RMC = Receive Mode Collision Detection (R1, R2, and C2 are needed for RMC Function)
Jumper 1 to 2 and 3 to 4
TMC = Transmit Mode Collision Detection
Jumper 1 to 3, open 2 and 4
R8 = 0 (Short)
DC – DC CONVERTER PINOUT
DC/DC Converters
Input = +12 V
Output = –9 V
+IN
–IN
+OUT
–OUT
1
2
4
5
1, 2
23, 24
11, 12
9, 10
Reliability INC.
2E12R9
Pulse Engineering
PE64540
Am7996EVAL-HW
3–5