R15UZ0002EU0100 Rev.1.00
Page 4
Oct 6, 2021
RTKA788152DE0000BU Evaluation Board Manual
1.2
Bus and Receiver Output Voltages
1.2.1
Set Up
Before connecting measurement equipment, set up the evaluation board and make sure to remove the JP1
socket, which is a jumper connection between two output channels A/Y and B/Z. Removal of JP1 socket allows for
measurement of output voltage across driver outputs. Follow the schematic diagram to enable driver by placing
sockets to connect DE_J positions 1 and 2. Enable the receiver by placing the socket to connect RE#_J positions
7 and 8. Placing a socket between positions 1 and 2 connects the Driver Enable function to V
CC
and activates the
driver. Otherwise, placing a socket between positions 7 and 8 connects the Receiver Enable function to ground,
and because this function is inverted, the receiver is activated. To ensure there is voltage across the bus, attach
the load resistor of 60
Ω
over the A/Y and B/Z channels. Without this resistive load, the bus is an open circuit.
Therefore, no voltage reading would be across the bus.
Attach V
CC
to the power supply and set the voltage to 5V
DC
. Attach the Oscilloscope channel 1 and channel 2
probes to the A/Y and B/Z channels accordingly for bus voltage reading. For channel 3, attach to RO for receiver
output voltage reading. Connect the pulse generator to driver input (DI) and set it up for square wave function.
Table 2. Receiver Truth Table
Inputs
Outputs
Function
RE
DE
A-B
RO
L
X
V
AB
≥
-0.05V
H
RO is data-driven high
L
X
-0.05 > V
AB
> -0.2V
Undetermined
Actively drives bus low
L
X
V
AB
≤
-0.02
L
RO is data-driven low
L
X
Inputs Open/Shorted
H
RO is failsafe-high
H
H
X
Z
Receiver disabled, RO is high-impedance
H
L
X
Z
Shutdown mode: driver and receiver disabled for more than 600ns
Figure 3. Setup for Bus and Receiver Output Voltage Measurement with Oscilloscope, Power Supply, and Function
Generator
‐
25V
Tr ack
Di s play
Limit
Recall
St ore
Out put
O n/Of f
Er ror
I /O
Conf i g
SELECT
Local
Cal ib ra te
Secur e
FUNCTION
>
<
Vol tage
Cur r ent
ADJUST
Pow er
O n
O ff
6V
±2 5V
CO M
+
±240
VD C
M A X
TO
± 25V
0-6V, 5A /0-±25V ,1A
Tr i ple O utp ut D C Pow er Su ppl y
E36 31A
+25V
+6V
+
7
3
9
4
6
2
1
5
8
.
0
+/
‐
M enu
AFG
Acqui re
For ce
Tr ig
Fr eq/Span
Am pl
M arker s
BW
RF
R
B1
B2
B3
M
Run/St op
Sin gle
Bks p
Ent er
Sin gle
M eas ure
Select
Fine
Aut oSet
Sear ch
Set /Clear
Level
Pus h
t o
Set
to
50%
Pos it i on
Pus h
t o
Cent er
Scale
M ark
M ult ip urpo se
b
M ult ip urpo se
a
M ath
Ref
Bus
Pos it i on
Scale
M enu
I ntens i ty
Cur s ors
1M
Ω
,13p F
≤
30 0VRMS
C AT
II;
50
Ω
,±5 VR MS
Tr igger
Hor i zont al
W ave
I ns pector
Ver t ical
Fr equency
50
Ω
+30dBm
( 1W )
max
±40V
DC
m ax
1
2
3
4
RF
R F
Save
M enu
Def ault
Setup
M e n u
O
f f
Ut il it y
D15
‐
D0
Save/Recal l
Pan
&
Zoo m
1
2
3
4
MD O4104C
Mixed
Dom ain
Os cillos cop e
6
GHz
1
GHz
5GS/s
LC L
O N
O FF
‐
10 V
+1 0V
EX T
INP UT
±20 V
LINE
LEVEL
CT RL
INPUT
±20 V
TR IG
INPUT
OUTPUT
MAN
1P ULSE
SE T
ST O/ RCL
LIMIT
COM PL
DIS AB LE
R MT
ADS
SR Q
NORM
TR IG
GAT E
E.WID
E.B UR
PE RC
DELC
WIDC
HIL C
BUR
PE R
DBL
DEL
DTY
WID
LEE
TR E
HIL
LOL
VERNIER
R ANGE
ST O
R CL
ms
µ s
ns
%
V
MODE
CT RL
8 11 2 A
PUL SE
GE NER AT OR
50
M Hz
HEWL ETT
PACKARD
