11

AUGUST 1999

TISPPBL2SD

PROGRAMMABLE OVERVOLTAGE PROTECTORS

FOR ERICSSON COMPONENTS PBL 3xxx SLICS

PR O D UC T

I N FO R M A T IO N

against negative overvoltage, the TISPPBL2S negative limiting voltage must be equal to or less than these

voltage values during the specified time periods.

The following table lists the protection requirements of three selections from different SLIC families. Two, the

PBL 3796 and the PBL 3762A, specify voltage withstand. The PBL 3796 specifies the negative voltages in

absolute terms and the PBL 3762A specifies the negative voltages in terms of voltage relative to the battery

Tertiary protection is incorporated in the PBL 386 20/1 SLIC and the withstand is specified in terms of current

into this protection. This type of SLIC also has more time periods specified for the current withstand values.

To co-ordinate the SLIC external secondary protection (TISPPBL2S) and the internal tertiary protection, a

The negative limiting voltage of the TISPPBL2S is defined as a 1 µs, -20 V pulse below the battery voltage

(Figure 2). This value does not exceed any of the voltage withstand levels listed in the SLIC withstand table. In

the positive polarity the TISPBL2S limits the maximum voltage to 8 V in a 1 µs period and between 1 V and

5 V for a 10 ms period. These values do not exceed the values listed in the SLIC withstand table.

Figure 15. TRANSIENT LIMITS FOR PBL 3762A WITHSTAND VOLTAGE

10 ms

1 µs

0.25 µs

PBL 3762A SLIC RING AND TIP VOLTAGE WITHSTAND

vs

TIME

0

5

10

15

Time

0.25 µs

1 µs

10 ms

-120

-110

-100

-90

-80

-70

-60

-50

D.C. and 10 ms pulse rating increased

to -70 V (independent of V

by use of series battery feed diode

V

V

V

V

BAT

AI6XBC