3/5

AN578

ANALYSIS

Table 1. Operating Region Definition

Table 1 shows the range of the three operating regions, while Figure 4, which illustrates region C, allows

us to determine the destruction time limit of each device versus the current through the structure (RMS

current at 25°C).

Figure 4. Characteristics of Region C (With Vgate = -48 V)

CONCLUSION

Figure 4: The devices in the LCPxxx family have common characteristics, divided into three regions:

a) Clamping mode, still functional after 15 minutes

b) Crowbar mode (firing) still functional after 15 minutes of test at 25°C

c) Crowbar mode, with a destruction time defined by Figure 4.

The given curves enable the appropriate series elements to be chosen, for example a PTC device.

OPERATING REGION

LCP 150

LCP 1512

LCP 1511

A/clamping

0 to 70 mA *

O to 70 mA *

O to 70 mA *

B/non destructive region

0.07 to 2 A *

0.07 to 1.2A*

0.07 to 0.8A *

C/destructive region

Over 2 A *

Over 1.2 A *

Over 0.8 A *

* RMS current

LCP150 / 1511 / 1512

0,5

1

2

5

10

20

50

100

0,5

1

2

5

10

20

t(S)

I(Arms)

LCP150

LCP1512

LCP1511