INM 5500 Rev 11
66
8 .5 .2 Testing MTL5553 - Isolator/power supply for 31 .25kbits/s fieldbuses
Make the safe and hazardous-area connections shown in figure 10.2 and, substituting appropriate
resistors at Rtest, carry out the following checks.
R
test
Voltage across terminals 2 and 1 (V
1)
Open-circuit
17.8 < V
1
<
19V
220Ω
11.5V < V
1
<
13.5V
10Ω
V
1
< 5V
20-35V dc
Vs-
Vs+
-ve
+ve
-ve
Host
(31.25kbit/s)
Terminator
1
2
4
5
6
3
2.6W Max
8
9
T
14
13
11
10
7
12
Link 7- 8 for Terminator
Hazardous Area
Safe Area
V
1
R
test
+
-
Top Label, MTL5553
Test circuit for MTL5553
