TISP2125F3 Power Innovations Limited, TISP2125F3 Datasheet - Page 12
TISP2125F3
Manufacturer Part Number
TISP2125F3
Description
DUAL SYMMETRICAL TRANSIENT VOLTAGE SUPPRESSORS
Manufacturer
Power Innovations Limited
Datasheet
1.TISP2125F3.pdf
(18 pages)
TISP2125F3, TISP2150F3, TISP2180F3
DUAL SYMMETRICAL TRANSIENT
VOLTAGE SUPPRESSORS
MARCH 1994 - REVISED SEPTEMBER 1997
protection voltage
capacitance
off-state capacitance
P R O D U C T
12
The protection voltage, (V
increase is dependent on the rate of current rise, di/dt, when the TISP is clamping the voltage in its
breakdown region. The V
V
can be made from the surge generator voltage rate of rise, dv/dt, and the circuit resistance.
As an example, the CCITT IX K17 1.5 kV, 10/700 µs surge has an average dv/dt of 150 V/µs, but, as the rise
is exponential, the initial dv/dt is higher, being in the region of 450 V/µs. The instantaneous generator output
resistance is 25
becomes 45
measured di/ dt and protection voltage increase will be lower due to inductive effects and the finite slope
resistance of the TISP breakdown region.
The off-state capacitance of a TISP is sensitive to junction temperature, T
of the dc voltage, V
with an ac voltage of 100 mV. The typical 25°C variation of capacitance value with ac bias is shown in Figure
21. When V
constant over the range of normal telecommunication frequencies.
(BO)
(250 V/ms) value by the normalised increase at the surge’s di/dt (Figure 7.) . An estimate of the di/dt
D
>> V
.
I N F O R M A T I O N
. If the equipment has an additional series resistance of 20
The maximum di/dt then can be estimated as 450/45 = 10 A/µs.
d
D
the capacitance value is independent on the value of V
, and the ac voltage, V
(BO)
1.05
1.00
0.95
0.90
0.85
0.80
0.75
0.70
(BO)
), increases under lightning surge conditions due to thyristor regeneration. This
1
value under surge conditions can be estimated by multiplying the 50 Hz rate
Normalised to V
DC Bias, V
APPLICATIONS INFORMATION
NORMALISED CAPACITANCE
RMS AC TEST VOLTAGE
V
d
- RMS AC Test Voltage - mV
D
= 0
10
d
Figure 21.
. All the capacitance values in this data sheet are measured
d
= 100 mV
vs
100
AIXXAA
1000
J
, and the bias voltage, comprising
d
. The capacitance is essentially
, the total series resistance
In practice the