4300H4(2005) Просмотр технического описания (PDF) - Bourns, Inc
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4300H4 Datasheet PDF : 13 Pages
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TISP4xxxH4BJ Overvoltage Protector Series
APPLICATIONS INFORMATION
Deployment
These devices are two terminal overvoltage protectors. They may be used either singly to limit the voltage between two conductors (Figure 12)
or in multiples to limit the voltage at several points in a circuit (Figure 13).
Th3
Th1
Th1
Th2
Figure 12. Two Point Protection
Figure 13. Multi-point Protection
In Figure 12, protector Th1 limits the maximum voltage between the two conductors to ±V(BO). This configuration is normally used to protect
circuits without a ground reference, such as modems. In Figure 13, protectors Th2 and Th3 limit the maximum voltage between each conduc-
tor and ground to the ±V(BO) of the individual protector. Protector Th1 limits the maximum voltage between the two conductors to its ±V(BO)
value. If the equipment being protected has all its vulnerable components connected between the conductors and ground, then protector Th1
is not required.
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
Voltage
Peak Current
Current
TISP4xxxH4
Series
Standard
Setting
V
Waveform
µs
Value
A
Waveform
µs
25 °C Rating
A
Resistance
Ω
2500
2/10
500
2/10
500
GR-1089-CORE
0
1000
10/1000
100
10/1000
100
1500
10/160
200
10/160
250
0
FCC Part 68
800
10/560
100
10/560
160
0
(March 1998)
1500
9/720 †
37.5
5/320 †
200
0
1000
9/720 †
25
5/320 †
200
0
I3124
1500
0.5/700
37.5
0.2/310
200
0
1500
37.5
ITU-T K.20/K.21
10/700
5/310
200
0
4000
100
† FCC Part 68 terminology for the waveforms produced by the ITU-T recommendation K.21 10/700 impulse generator
If the impulse generator current exceeds the protector’s current rating, then a series resistance can be used to reduce the current to the
protector’s rated value to 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 generator’s peak voltage by the protector’s rated
current. The impulse generator’s fictive impedance (generator’s 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 11, the appropriate series resistor value can be calculated for ambient
temperatures in the range of -40 °C to 85 °C.
NOVEMBER 1997 - REVISED FEBRUARY 2005
Specifications are subject to change without notice.
Customers should verify actual device performance in their specific applications.
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