Kikusui TOS5050A, Operation Manual, Page: 86 / 120

6-26 TOS5051A/5050A
tester to that of the external device. (Do not connect the ISOL COM pins to the
shielding line or an earth ground.) This will isolate the SIGNAL I/O circuits from
the external environments and will become more resistant against noise.
• Shorting of the high voltage output terminals of the tester may generate noise that
can cause interference to peripheral devices. If you need to suppress the interfer-
ence, connect a resistor (470
Ω
or thereabout) between the end of the high test
lead and the DUT and another resistor of the same resistance between the end of
the low test lead and the DUT (in positions as close to the DUT as possible).
These resistors are very effective for suppression of the noise interference. Pay
attention to the wattage and the maximum working voltage of the resistors. When
the upper cutoff current is not greater than 10 mA, resistors of 470
Ω
(Rated
Power: 3 W, Impulse Dielectric Withstanding Voltage: 30 kV) will be appropriate.
When you have connected these resistors, the test voltage that is actually applied
to the DUT will be slightly lower (approximately 10 V when the current that
fl ows
through the DUT is 10 mA) than the output terminal voltage due to the voltage
drops caused by the resistors.
However, it is very effective in reducing noise effects.
■
Reference start/stop circuit
When using make-contact devices
To control with make-contact devices such as relays and switches, refer to Fig. 6-4.
You may replace the contacts with logic element transistors, FETs, or photocou-
plers.
When using logical elements
To control with logic elements (Low-active control), refer to Fig. 6-5.
• Each “ic” rating must be 5 mA or more.
Fig. 6-4 Fig. 6-5
DESCRIPTION
1 2 3 4 5 6 7
13 12 11 10 9 8
START
STOP ENABLE
14
START STOP ENABLE
1 2 3 4 5 6 7
14 13 12 11 10 9 8
ic
ic
ic
CAUTION