Automatic Level Control
Function
Description
The automatic level control (
alc
) function regulates the actual test
level (voltage across the DUT, or current through the DUT) to your
desired level. So by using this function, the test signal voltage or
current level at the DUT can b e held constant.
When the automatic level control function is used, the oscillator level
settings are limited as follows.
When Option 001 is not installed, or the high p ower mo de is set to
OFF
Voltage Level: 10 mV
rms
to 1 V
rms
Current Level: 100
A
rms
to 10 mA
rms
When the high p ower mo de is set to ON
Voltage Level: 10 mV
rms
to 10 V
rms
Current Level: 100
A
rms
to 100 mA
rms
Note
When the ALC function is active, if the oscillator lev
el setting
exceeds the ab ove limits, the ALC function is automatically set to
OFF and the setting value is entered as a normal oscillator level.
Note
The automatic level control is achieved using feedback with the level
monitor function as shown in Figure 4-4. The feedback op eration
performs a level measurement/OSC level adjustment 2 to 6 times
per measurement. (The time required (n in the following form
ula)
depends on the device being tested. The more non-linear the device
is, the greater the time required.) When the ALC function can't
regulate the level using 6 output level measurement/adjustment
cycles (when a device has non-linear characteristics, the ALC
function may stop b efore the 6 output level measurement/adjustment
cycles), the ALC function stops, and a warning message
ALC unable
to regulate
is displayed, and sets the oscillator level to equal your
setting value, op en-loop, the output level will be the same as when
ALC is set to OFF. The time required for the ALC function to
operate is calculated using the following formula.
(meas.time (SHORT) + approx. 115 msec.)
2
n
Where, n = 2 (min.)
n = 6 (max.)
4-6 MEAS SETUP Menu
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