8-4
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2600S-901-01 Rev. C / January 2008
Section 8: Source-Measure Concepts
Series 2600 System SourceMeter® Instruments Reference Manual
Pulse sweeps
The Series 2600 can also perform the following pulse sweeps:
• Fixed voltage pulse
• Fixed current pulse
These sweeps are similar to those discussed above, except the source level at each sweep step is
a pulse instead of a constant level. The pulse width (on time) and pulse delay (off time) can be
programmed for each type of pulse mode sweep.
shows an example of a three-pulse
sweep. See
in Section 5 and
described later in this section for
more information.
Pulse sweeps are used in applications where thermal response is measured or where sustained
power levels can damage the external Device Under Test (DUT).
Figure 8-2
Pulse sweep example
Pulse
On
Time
Measure
#1
Point #1
(Start)
Pulse
Off
Time
Pulse
On
Time
Measure
#2
Point #2
Pulse
Off
Time
Pulse
On
Time
Point #3
(Stop)
Measure
#3
Pulse
Off
Time
Bias
Overheating protection
Proper ventilation is required to keep the SourceMeter from overheating. Even with proper
ventilation, the SourceMeter can overheat if the ambient temperature is too high or the
SourceMeter is being operated in sink mode for long periods of time. The SourceMeter has an
over-temperature protection circuit that will turn the output off in the event that the instrument
overheats. If the output trips due to overheating, a message indicating this condition will be
displayed. You will not be able to turn the output back on until the instrument cools down.
Power equations to avoid overheating
To avoid overheating, each SourceMeter channel should not be operated in a manner that would
force it to exceed the maximum duty cycle (DC
MAX
) computed using the
below. Factors such as the ambient temperature, quadrant of operation, and high
power pulse levels (if applicable) affect the maximum duty cycle. Exceeding the calculated
maximum duty cycle may cause the SourceMeter’s over temperature protection mechanism to
engage. When this happens, an error message will be displayed, and the SourceMeter output(s)
will be disabled until the internal temperature of the SourceMeter is reduced to an acceptable
level.
You do
not
have to be concerned about overheating if
all
of the following are true:
• The SourceMeter is being used as a power source and not a power sink.
• The ambient temperature is
≤
30°C.