TOELLNER Electronic Instrumente GmbH
6
2.2
E-10, Short interruptions
‒
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-10 test the DUT is replaced by a reference resistor of 1
Ω
± 5 %
resp. 100
Ω
± 5 % of low parasitic inductance ( Fig. 1).
To avoid the addition of cable inductivity, the reference resistor shall be connected as close
to the output sockets of the TOE 9260 as possible. The reference resistors of the
TOE 9260/100 kit may be connected directly to the output sockets without use of cables.
Because of the high power loss in case of the 1
Ω
resistor operated at 11 V according to the
LV 124, the test setup should be prepared in the powerless state. Test execution should be
kept as short as possible.
2.3
LV 124, Test E-13, Pin interruption
The test E-13 has to be applied to signal pins as well as to ground pins. For both situations,
the test assemblies are explained in the following.
2.3.1
E-13, interruption of signal pins
For the interruption of a signal pin, a signal line switch of the TOE 9260 is used. Such a
signal line switch is applicable for a pin current up to 1 A.
If up to 2 A have to be switched, two signal line switches can be paralleled. It is not
recommended to operate more than two switches in parallel. With three or four switches in
parallel the timing requirements of the LV 124-2013 cannot be fulfilled with a 1 k
Ω
reference
resistor. (For applications different from the LV 124 / LV 148 standards, there are four signal
line switches available in the TOE 9260; if e.g. differential pairs or a 4-pole connection shall
be switched at once.)
Fig. 2 shows the test assembly with use of one of the signal line switches of the TOE 9260.
Only one pin has to be interrupted at one time. The test is then sequentially carried out for
every signal pin of the DUT.
Fig. 2:
Test assembly for LV 124, E-13; interruption of a signal pin
