Surging
Ideas
TVS Diode Application Note
PROTECTION PRODUCTS
LC03-3.3 Testing to
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
derived current waveform has a duration of 2/10碌s.
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鈥檚 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 8x20碌s surge. The 8/20碌s pulse is longer in
duration than the 2/10碌s. 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.
SI01-06
1
8
8x20 us
Current
Source
tester
2
7
3
6
4
5
Figure 1 . Common Mode
1
8
8x20 us
Current
Source
tester
2
7
3
6
4
5
Figure 2 . Differential Mode
Revision 2/4/2002
www.semtech.com
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