Long line protection

AN2053

8/15

Doc ID 10917 Rev 2

Figure 10.

LCP15xx behavior during 10/700µs negative surge

Figure 10 shows both surge current through the TIP pin of a LCP15xx and the voltage

across it when submitted to a 20 A 10/700 µs ITU-T K20 surge. The TIP voltage falls to the

battery voltage (-48 V) and then fires.

Figure 11.

LCP15xx behavior during 10/700µs positive surge

During a positive surge on TIP wire, the diode between TIP to GND conducts and then all

the surge current flows through the ground. This behavior is shown in Figure 11.

V tip : 10V/div

I line : 5 A /div

V tip : 1V/div

I line : 5 A /div