AG

SI01-06
Surging Ideas
TVS Diode Application Note
PROTECTION PRODUCTS
LC03-3.3 Testing to
derived current waveform has a duration of 2/10µs.
Since this is a test using a voltage source, the
impedance of the unit under test can decrease the
amount of current actually seen by the circuit. The
test performed on Semtech’s LC03-3.3 is a current
source test. The purpose of using a current source
tester is to insure that the current through the device
is actually 100A. This provides for a worse case
scenario and insures that the part will operate under
worse case conditions. In addition, the test performed
is an 8x20µs surge. The 8/20µs pulse is longer in
duration than the 2/10µs. This means the test
performed on the devices is actually a higher energy
pulse than required by the Bellcore intra-building
standard. Figure 1 shows the test setup for common
mode. Figure 2 shows the test setup for differential
mode.
Bellcore 1089 Intra-building
Test Setup
The intra-building lightning surge required by Bellcore
1089 is defined by a double exponential waveform.
For testing purposes this is achieved with a voltage
source and a resistor/capacitor network. The lines are
tested in both metallic (line-to-line) and longitudinal
(line-to-ground) configuration. For metallic mode, the
standard calls for an 800V (open circuit voltage) surge
with a 100A minimum (short circuit current) coming out
of the tester. For a longitudinal mode, it calls for a
1500V (open circuit voltage) surge with a 100A (short
circuit current) minimum coming out of the tester. The
8x20 us
Current
Source
tester
1
8
2
7
3
6
4
5
Figure 1 . Common Mode
8x20 us
Current
Source
tester
1
8
2
7
3
6
4
5
Figure 2 . Differential Mode
Revision 2/4/2002
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SI01-06
Surging Ideas
TVS Diode Application Note
PROTECTION PRODUCTS
Test Results
voltage of the LC03-3.3 from pin 1 to 2 during a 100A
8/20µs surge. The part is electrically tested after each
surge to verify that the device is still operative. Figure
4 shows the typical clamping curve of the LC03-3.3
during an 8/20µs surge from 1 to 100A. Two curves
are shown, line to line (differential mode) and line to
ground (common mode).
An oscilloscope was used to display the voltage across
the LC03-3.3 during a 100A 8/20µs double
exponential pulse. Figure 1 is the configuration of the
test performed. The current output by the tester is
monitored on Ch1. The current ratio is 20A/100mV.
The voltage between pin 1 and 2 of the LC03-3.3 is
monitored on Ch2. Figure 3 shows the clamping
Figure 3. LC03-3.3 Clamping Voltage During 100A 8x20µs Surge
20
Clamping Voltage (V)
Line-To-Line
15
10
Line-To-Ground
Waveform
Parameters:
tr = 8µs
td = 20µs
5
0
0
20
40
60
80
100
Peak Pulse Current (A)
Figure 4. LC03-3.3 Typical Clamping Voltage vs. Peak Pulse Current
 2002 Semtech Corp.
2
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