TOELLNER Electronic Instrumente GmbH
7
2.3.2
E-13, interruption of signal pins
‒
reference measurements
This section applies to LV 124, version 2013 only. That standard requires reference
measurements before an interruption test is carried out with the DUT. Such a reference
measurement gives proof of the slew rate of the switching operation. For the reference
measurements of the E-13 test the DUT is replaced by a reference resistor of 1
Ω
± 5 %
resp. 1 k
Ω
± 5 % of low parasitic inductance.
To avoid the addition of too high cable inductivity, the reference resistor shall be connected
close to the signal line switch by closely spaced wires. The switchable reference resistor
TOE 9260/104 may be connected to power source and signal line switch by provided
suitable cables.
Due to the 1 A current limit of a signal line switch, the measurement with the 1
Ω
resistor
shall be carried out at a voltage of 1 V as shown in Fig. 3. Applying such a low voltage level
instead of the actual voltage of the signal pin of the control unit has no significant influence
on the timing of the measured waveform. Reference measurements with the 1 k
Ω
resistor
can be executed with the same voltage as the normal DUT operation voltage.
Fig. 3:
Measurement with a 1
Ω
reference resistor at a voltage level of 1 V
If the DUT is tested with two paralleled signal line switches ( 2.3.1), the reference
measurements have to be carried out with the same configuration of paralleled switches.
The test voltage for the 1
Ω
reference resistor may be increased up to 2 V.
