NOVEMBER 2001 - REVISED FEBRUARY 2005

Specifications are subject to change without notice.

Customers should verify actual device performance in their specific applications.

TISP43xxMMAJ/BJ Overvoltage Protector Series

TIA/EIA-IS-968 (FCC Part 68) System Voltage Levels

The protector should not clip or limit the voltages that occur in normal system operation. If the maximum system voltages are not known, then

designers often used the voltages for the FCC Part 68 “B” ringer. The “B” ringer has a d.c. voltage of 56.5 V and a maximum a.c. ring voltage

of 150 V rms. The resultant waveform is shown in Figure 11. The maximum voltage is -269 V, but, because of possible wiring reversals, the

protector should have a working voltage of ±269 V minimum. The TISP4350MM protector meets this requirement with a working voltage,

ringing voltage.

ADSL System Voltage Levels

The ADSL signal can be as high as ±15 V and this adds to the POTS signal making a peak value of -284 V. This increased signal value of

-284 V would be clipped by the TISP4350MM, which only allows for a -275 V signal. The TISP4360MM has been specified to overcome this

problem by having a higher working voltage of ±290 V. Figure 13 shows the TISP4360MM voltages relative to the -284 V peak ADSL plus

POTS ringing voltage. The ±15 V ADSL signal is shown as a gray band in Figure 13.

Figure 11.

-300 V

-56.5 V d.c.

-200 V

-100 V

0

100 V

200 V

-269 V

+156 V

AI4XAD

Figure 12.

-370

-360

-350

-340

-330

-320

-310

-290

-280

-270

-260

-250

-240

-230

-300

TISP4 350MM

WORKING VOLTAGE V

DRM

PROTECTION VOLT AGE V

(BO)

AI4HAEA

-269 V

RINGING PEAK

-275 V

-350 V

Figure 13.

-370

-360

-350

-340

-330

-320

-310

-290

-280

-270

-260

-250

-240

-230

-300

PROTECTION VOLT AGE V

(BO)

-284 V PEAK

ADSL + RINGING

TISP4 360MM

WORKING VOLTAGE V

DRM

AI4HAFA

-290 V

-360 V