Specifications are subject to change without notice.

Customers should verify actual device performance in their specific applications.

JANUARY 1998 - REVISED FEBRUARY 2005

ISDN Device Selection

The ETSI Technical Report ETR 080:1993 defines several range values in terms of maximum and minimum ISDN feeding voltages. The

following table shows that ranges 1 and 2 can use a TISP5110H3BJ protector and ranges 3 to 5 can use a TISP5150H3BJ protector.

Impulse Testing

To verify the withstand capability and safety of the equipment, standards require that the equipment is tested with various impulse wave forms.

The table below shows some common values.

If the impulse generator current exceeds the protector’s current rating then a series resistance can be used to reduce the current to the

protector’s rated value and so prevent possible failure. The required value of series resistance for a given waveform is given by the following

calculations. First, the minimum total circuit impedance is found by dividing the impulse generator’s peak voltage by the protector’s rated

current. The impulse generator’s fictive impedance (generator’s peak voltage divided by peak short circuit current) is then subtracted from the

minimum total circuit impedance to give the required value of series resistance. In some cases the equipment will require verification over a

temperature range. By using the rated waveform values from Figure 10, the appropriate series resistor value can be calculated for ambient

temperatures in the range of -40 °C to 85 °C.

If the devices are used in a star-connection, then the ground return protector, Th3 in Figure 13, will conduct the combined current of protectors

Th1 and Th2. Similarly in the bridge connection (Figure 14), the protector Th1 must be rated for the sum of the conductor currents. In these

cases, it may be necessary to include some series resistance in the conductor feed to reduce the impulse current to within the protector’s

ratings.

TISP5xxxH3BJ Overvoltage Protection Series

APPLICATIONS INFORMATION

Range

Feeding Voltage

Standoff Voltage

V

Device Name

Minimum

V

Maximum

V

15169-75

TISP5095H3BJ

26670

-80

TISP5110H3BJ

391

99

-120

TISP5150H3BJ

490

110

5

105

115

Standard

Peak Voltage

Setting

V

Voltage

Waveshape

µs

Peak Current

Value

A

Current

Waveshape

µs

TISP5xxxH3BJ

25 °C Rating

A

Series

Resistance

Ω

GR-1089-CORE

2500

2/10

500

2/10

500

0

1000

10/1000

100

10/1000

100

TIA-968-A

1500

10/160

200

10/160

250

0

800

10/560

100

10/560

160

0

1500

9/720 †

37.5

5/320 †

200

0

1000

9/720 †

25

5/320 †

200

0

I3124

1500

0.5/700

37.5

0.2/310

200

0

ITU-T K.20/21/45

1500

4000

6000

10/700

37.5

100

150

5/310

200

0

† TIA-968-A terminology for the waveforms produced by the ITU-T recommendation K.21 10/700 impulse generator.