TISP5070H3BJ, TISP5080H3BJ, TISP5110H3BJ, TISP5150H3BJ
FORWARD-CONDUCTING
UNIDIRECTIONAL THYRISTOR OVERVOLTAGE PROTECTORS
JANUARY 1998 - REVISED MARCH 1999
ISDN device selection
The ETSI Technical Report ETR 080:1993 defines several range values in terms of maximum and minimum
ISDN feeding voltages. The following table shows that ranges 1 and 2 can use a TISP5110H3BJ protector
and ranges 3 to 5 can use a TISP5150H3BJ protector.
FEEDING VOLTAGE
STANDOFF VOLTAGE
RANGE MINIMUM MAXIMUM
V
DEVICE #
DRM
V
51
66
91
90
105
V
V
1
2
3
4
5
69
-80
TISP5110H3BJ
TISP5150H3BJ
70
99
110
115
-120
impulse testing
To verify the withstand capability and safety of the equipment, standards require that the equipment is tested
with various impulse wave forms. The table below shows some common values.
PEAK VOLTAGE
SETTING
V
VOLTAGE
WAVE FORM
µs
PEAK CURRENT
CURRENT
TISP5xxxH3
SERIES
STANDARD
VALUE
A
WAVE FORM 25 °C RATING RESISTANCE
µs
A
Ω
2500
2/10
500
100
200
100
37.5
25
2/10
500
100
250
160
200
200
200
GR-1089-CORE
0
1000
10/1000
10/160
10/1000
10/160
10/560
5/320 †
5/320 †
0.2/310
1500
0
0
0
0
0
FCC Part 68
(March 1998)
800
10/560
1500
9/720 †
9/720 †
0.5/700
1000
I3124
1500
37.5
37.5
100
1500
ITU-T K20/K21
10/700
5/310
200
0
4000
† FCC Part 68 terminology for the waveforms produced by the ITU-T recommendation K21 10/700 impulse generator
If the impulse generator current exceeds the protectors current rating then a series resistance can be used to
reduce the current to the protectors rated value and so prevent possible failure. The required value of series
resistance for a given waveform is given by the following calculations. First, the minimum total circuit
impedance is found by dividing the impulse generators peak voltage by the protectors rated current. The
impulse generators fictive impedance (generators peak voltage divided by peak short circuit current) is then
subtracted from the minimum total circuit impedance to give the required value of series resistance. In some
cases the equipment will require verification over a temperature range. By using the rated waveform values
from Figure 10, the appropriate series resistor value can be calculated for ambient temperatures in the range
of -40 °C to 85 °C.
If the devices are used in a star-connection, then the ground return protector, Th3 in Figure 13, will conduct
the combined current of protectors Th1 and Th2. Similarly in the bridge connection (Figure 14), the protector
Th1 must be rated for the sum of the conductor currents. In these cases, it may be necessary to include some
series resistance in the conductor feed to reduce the impulse current to within the protectors ratings.
a.c. power testing
The protector can withstand currents applied for times not exceeding those shown in Figure 8. Currents that
exceed these times must be terminated or reduced to avoid protector failure. Fuses, PTC (Positive
Temperature Coefficient) resistors and fusible resistors are overcurrent protection devices which can be used
P R O D U C T
I N F O R M A T I O N
10
POINN [ POWER INNOVATIONS LTD ]
