DocID11830 Rev 2

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AN2266

LCP concept

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Table 1 shows the most commonly used worldwide ESD standards. Generally, level 4 is

required.

Section 2 presents the protection concept used for SLICs on both short and long line

applications.

2

LCP concept

Figure 6. LCP152xx concept behavior

Figure 6 shows the classic protection circuit using the LCP152xx crowbar concept. This

topology has been developed to protect the new high voltage SLICs. It allows the system to

be programmed for the negative firing threshold while the positive clamping value is fixed at

GND.

base of the transistor T and then injects a current in the gate of the thyristor Th. Then Th

turns on and the whole surge current shunts to ground (GND). After the surge, when the

Table 1. IEC61000-4-2 ESD surge standard

1a contact discharge

1b air discharge

Level

Test voltage (kV)

Level

Test voltage (kV)

12

12

24

24

36

38

48

4

15

1.

“X” is a level to be defined

Special

X(1)

Special

L 1

L 2

Gate

-Vbat

C

T

TIP

RING

GND

Th

D

Rs1

Rs2

Ig

ID

V tip

V Ring

Line side