6247G/6247C DC Voltage Current Source/Monitor Operation Manual
5.1.3 Preventing Oscillation
5-4
5.1.3
Preventing Oscillation
The DUT itself may oscillate, or the 6247G/6247C may oscillate if capacitance or inductance exceeding
the specified value is connected (due to stray capacitance or retained inductance from connected cables, a
scanner, or a fixture).
Judge whether the DUT or the 6247G/6247C oscillates by the oscillation frequency. The 6247G/6247C
does not oscillate at 2 MHz or over.
5.1.3.1
Preventing 6247G/6247C Oscillation
1. Causes
•
Oscillation may occur because of the capacitive load in voltage source or while the voltage lim-
iter is activated.
•
Oscillation may occur because of the inductive load in current source or while the current lim-
iter is activated.
2. Solution
Remove the causes of oscillation according to the following procedure:
1. Verify if the load capacitance or load inductance does not exceed the maximum
load capacitance or load inductance specified in Chapter 9, "SPECIFICA-
TIONS."
2. Check if the 6247G/6247C still oscillates when cables of the shortest lengths are
connected.
3. If the shorter cables stop the oscillation, then connect the 6247G/6247C and the
DUT as shown in Figure 5-3 to reduce the capacitance and inductance of cables
and other devices.
4. If the oscillation does not stop even if the cables are the shortest possible, insert
an allowable resistor for the DUT as shown in Figure 5-5.
NOTE:
When more than one power supply unit is used, oscillation in one unit may
cause oscillation in other units. Then find the particular power supply that
may stop the oscillation, following the procedure from 1 to 4 above.
Figure 5-3 Reducing Stray Capacitance and Lead Inductor
6247G/C
Wire HI OUTPUT and LO OUTPUT in twisted pairs.
Wire HI SENSE and LO SENSE in twisted pairs.
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2
