DocID11830 Rev 2

13/16

AN2266

Long line protection

16

The LCP02-150B1 and the PTC still continue to operate properly after the test in

accordance with the K20 A criterion.

power contact

Figure 19 shows the voltage across the TIP pin of LCP02-150B1, the gate voltages and

ITU-T K20 power contact test. For power contact tests, the PTC heats up and the

LCP02-150B1 behaves like the LCP1521S in the negative domain. That is, from the

moment that the negative gate current becomes lower than the negative gate triggering

current of the LCP02-150B1, this device does not fire anymore, but only clamps. It still fires

in the positive domain because its positive gate is highly sensitive. The voltage trip at the

TIP pin is between both battery voltages ±65 V.

The LCP02-150B1 and the PTC still continue to operate properly after the test in

accordance with K20 A criterion, while this test with 10

Ω requires only the K20 B criterion.

I surge: 5A /div

V Tip: 20V/div

+Vb: 20V/div

0

-Vbat: 20V/div