TISP61089
DUAL FORWARD-CONDUCTING P-GATE THYRISTORS
PROGRAMMABLE OVERVOLTAGE PROTECTORS
NOVEMBER 1995 - REVISED FEBRUARY 1998
section 4.5.12 - first-level power fault testing
The most significant tests are a long duration (900 s) medium current test and a higher current tests of 60 one
second power applications. As shown in table 4, the peak currents for these tests are 2x0.37 A and 2x1.3 A
respectively. The TISP61089 will survive both these conditions as its ratings are 2x0.93 A and 2x4.5 A for
these time periods
table 4. first-level power fault currents
A.C.
OPEN-CIRCUIT SHORT-CIRCUIT
SOURCE
RESISTANCE
Ω
TOTAL CIRCUIT
RESISTANCE
Ω
ITRMS
A
ITM
A
DURATION RMS VOLTAGE
RMS CURRENT
A
s
V
1
1
200
400
600
1000
50
0.33
0.67
1
600
600
600
1000
150
590
640
640
640
1040
190
630
2x0.31
2x0.63
2x0.94
2x0.96
2x0.26
2x0.16
2x0.44
2x0.88
2x1.3
1
1
1
2x1.3
900
900
0.33
0.17
2x0.37
2x0.22
100
Using a 25 Ω series resistor will result in table 4. ITM column values of 2x0.45, 2x0.9, 2x1.4, 2x1.4, 2x0.4 and
2x0.23. The TISP61089 will survive these peak current values as they are lower than the TISP61089 ratings.
section 4.5.13 - second-level power fault testing
The two most significant tests are a long duration (900 s) medium current test and a higher current 5 s test.
As shown in table 5, the peak currents for these tests are 2x17 A and 2x7.7 A respectively. For the
TISP61089 to survive this test, the series current limiting element must operate within 0.1 s and 0.5 s
respectively.
table 5. second-level power fault currents
TOTAL
A.C.
OPEN-CIRCUIT SHORT-CIRCUIT
SOURCE
RESISTANCE
Ω
ITRMS
A
ITM
A
CIRCUIT
RESISTANCE
Ω
DURATION RMS VOLTAGE
CURRENT
A
s
V
5
600
600
120
277
100
300
600
60
7
10
86
50
126
45
2x12
2x4.8
2x2.7
2x5.4
2x0.32
2x0.96
2x1.9
2x17
2x6.8
2x3.8
2x7.7
2x0.45
2x1.4
2x2.7
5
900
900
900
900
900
25
5
25
11
51
0.37
1.1
2.2
273
273
273
313
313
313
Using a 25 Ω series resistor will result in table 5. ITM column values of 2x24, 2x7.7, 2x5.7, 2x11, 2x0.47, 2x1.4
and 2x2.9. The TISP61089 will probably fail for a peak current level of 2x24 A and the series current limiting
P R O D U C T
I N F O R M A T I O N
11
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