1N6373, ICTE-5, MPTE-5,
through
1N6389, ICTE-45, C, MPTE-45, C
1000
500
I Z, ZENER CURRENT (AMPS)
200
100
50
20
10
5
2
1
0.3
0.5 0.7 1
2
3
5 7 10
20 30
∆V
Z, INSTANTANEOUS INCREASE IN VZ ABOVE VZ(NOM) (VOLTS)
1
0.7
0.5
0.3
DERATING FACTOR
0.2
0.1
0.07
0.05
0.03
0.02
10
µs
0.01
0.1
0.2
0.5
1
2
5
10
D, DUTY CYCLE (%)
20
TL = 25°C
tP = 10
µs
VZ(NOM) = 6.8 to 13 V
20 V
43 V
24 V
1000
500
I Z, ZENER CURRENT (AMPS)
200
100
50
20
10
5
2
1
TL = 25°C
tP = 10
µs
1N6267A/1.5KE6.8A
through
1N6303A/1.5KE200A
VZ(NOM) = 6.8 to 13 V
20 V
24 V
43 V
75 V
180 V
120 V
0.3
0.5 0.7 1
2
3
5 7 10
20 30
∆V
Z, INSTANTANEOUS INCREASE IN VZ ABOVE VZ(NOM) (VOLTS)
Figure 6. Dynamic Impedance
PULSE WIDTH
10 ms
1 ms
100
µs
50
100
Figure 7. Typical Derating Factor for Duty Cycle
APPLICATION NOTES
RESPONSE TIME
In most applications, the transient suppressor device is
placed in parallel with the equipment or component to be pro-
tected. In this situation, there is a time delay associated with
the capacitance of the device and an overshoot condition as-
sociated with the inductance of the device and the inductance
of the connection method. The capacitance effect is of minor
importance in the parallel protection scheme because it only
produces a time delay in the transition from the operating volt-
age to the clamp voltage as shown in Figure A.
The inductive effects in the device are due to actual turn-on
time (time required for the device to go from zero current to full
current) and lead inductance. This inductive effect produces
an overshoot in the voltage across the equipment or
component being protected as shown in Figure B. Minimizing
this overshoot is very important in the application, since the
main purpose for adding a transient suppressor is to clamp
voltage spikes. These devices have excellent response time,
typically in the picosecond range and negligible inductance.
However, external inductive effects could produce unaccept-
able overshoot. Proper circuit layout, minimum lead lengths
500 Watt Peak Power Data Sheet
4-4
and placing the suppressor device as close as possible to the
equipment or components to be protected will minimize this
overshoot.
Some input impedance represented by Zin is essential to
prevent overstress of the protection device. This impedance
should be as high as possible, without restricting the circuit op-
eration.
DUTY CYCLE DERATING
The data of Figure 1 applies for non-repetitive conditions
and at a lead temperature of 25°C. If the duty cycle increases,
the peak power must be reduced as indicated by the curves of
Figure 7. Average power must be derated as the lead or
ambient temperature rises above 25°C. The average power
derating curve normally given on data sheets may be
normalized and used for this purpose.
At first glance the derating curves of Figure 7 appear to be in
error as the 10 ms pulse has a higher derating factor than the
10
µs
pulse. However, when the derating factor for a given
pulse of Figure 7 is multiplied by the peak power value of
Figure 1 for the same pulse, the results follow the expected
trend.
Motorola TVS/Zener Device Data
MOTOROLA [ MOTOROLA, INC ]
