TISPPBL1D, TISPPBL1P, TISPPBL2D, TISPPBL2P
DUAL FORWARD-CONDUCTING P-GATE THYRISTORS
FOR ERICSSON COMPONENTS SLICS
AUGUST 1997 - REVISED DECEMBER 1999
impulse generator
A Keytek ECAT E-Class series 100 with an E502 surge network was used for testing. The E502 produces a
0.5/700 voltage impulse. This particular waveform was used as it has the fastest rate of current rise (di/dt) of
the commonly used lightning surge waveforms. This maximises the measured limiting voltage. Figure 4
shows the current wavefront through the DUT. To produce a peak test current level of ±20 A, the E502
charging voltage was set to ±1960 V. Figure 5 shows the DUT current di/dt. Initially the wavefront current rises
at 60 A/µs, this rate then reduces as the peak current is approached. At the TISPPBLx V(BO) condition the
di/dt is about 50 A/µs.
limiting voltage levels
Fifty devices were measured in the test circuit of Figure 3. The 50 devices were made up from groups of 5
devices taken from 10 separately processed device lots. Figure 7 shows the total waveform variation of the
thyristor limiting voltage across the 50 devices. This shows that the largest peak limiting voltage (Breakover
voltage, V(BO)) is -62 V, a 12 V overshoot beyond the -50 V gate reference supply, VB. The limiting voltage
exceeds the gate reference supply voltage level for a period (t(BR)) of about 0.4 µs.
Figure 9 and Figure 11 show these two waveform parameters in terms of device population. In Figure 9, the
limiting voltage is shown in terms of the overshoot beyond the gate reference supply (VB - V(BO)). Removing
the gate reference voltage level magnifies the thyristor limiting voltage variation and shows the data
stratification caused by the oscilloscope digitisation. Extrapolating the data trend indicates that the overshoot
is less than 14 V at the 99.997% level (equal to 30 ppm of the population exceeding 14 V, equivalent to +4
sigma point of a normal distribution). In Figure 11, extrapolating the thyristor data trend to the 99.997% level
indicates a maximum breakdown time, t(BR), of 0.5 µs. Figure 12 shows that increasing the temperature up to
85 °C increases the thyristor peak limiting voltage by 2.4%, giving a maximum 85 °C peak limiting voltage of
1.024x(-50-14) = -65.5 V. Over the -40 °C to 85 °C temperature range the TISPPBLx is specified to have a
maximum V(BO) value of -70 V and a breakdown time, t(BR), of 1 µs.
Figure 8 shows the total waveform variation of the diode limiting voltage across the 50 devices. The peak
limiting voltage (Peak Forward Recovery Voltage VFRM) is less than 6 V, and this value includes the 2 V of
magnetically induced noise in the probe. Figure 9 shows that extrapolated 99.997% level is about 5.5 V. In
Figure 11, extrapolating the diode data trend to the 99.997% level indicates a maximum forward recovery
time, tFR, of 0.1 µs. Figure 12 indicates that there is about a 10% uplift by increasing the temperature to 85 °C.
This gives a maximum 85 °C peak limiting voltage of 1.1x(5.5) = 6.1 V. Over the -40 °C to 85 °C temperature
range, the TISPPBLx is specified to have a maximum VFRM value of 8 V and a maximum forward recovery
time of 1 µs.
Diodes do not switch to a much lower voltage like thyristors, so the diode limiting voltage applies for the whole
impulse duration. Forward voltages of 1 V or less are normally considered safe. Figure 10 shows that the
lowest current 1 V condition occurs at -40 °C with a current of 0.3 A. When the TISPPBLx is tested with the
rated 10/1000 impulse it would take about 8 ms for the current to decay from 30 A to 0.3 A. Over the -40 °C to
85 °C temperature range, the TISPPBLx is specified to have a VF below 1 V within 10 ms.
SLIC protection requirements
This clause discusses the voltage withstand capabilities of the various Ericsson Components SLIC groups
and compares these to the TISPPBLx protector parameters. The examples provided are intended to provide
designers information on how the TISPPBLx protector and specific SLICs work together. Designers should
always follow the circuit design recommendations contained in the latest edition of a SLIC data sheet.
temperature range
Some SLICs are rated for 0 °C to 70 °C operation, others for -40 °C to 85 °C operation. The TISPPBLx
protector is specified for -40 °C to 85 °C operation and so covers both temperature ranges.
P R O D U C T
I N F O R M A T I O N
10
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