Slew Rate & Minimum Transient Time; Start/Stop Current Loading - Chroma 63200 Series Operation & Programming Manual

3.7 Slew Rate & Minimum Transient Time
Slew rate is defined as the change in current over time. A programmable slew rate allows a
controlled transition from one load setting to another to minimize induced voltage drops on
inductive power wiring, or to control induced transients on a test device. If the transient from
one setting to another is large, the actual transient time can be calculated by dividing the
current transition by the slew rate. The actual transition time is defined as the time required
for the change of input from 10% to 90% or from 90% to 10% of the programmed excursion.
If the transition from one setting to another is small, the small signal bandwidth of Load will
limit the minimum transition time for all programmable slew rates. Because of the limit, the
actual transition time is longer than the expected time based on the slew rate. Therefore,
both minimum transition time and slew rate must be considered in the determination of actual
transition time. The minimum transition time is from 24 µs to 6 ms depending on the slew
rate setting.
3.8

Start/Stop Current Loading

To simulate the transient characteristics of load to UUT, the critical problems are when and
how the Load starts current loading to UUT. You may set the conducting voltage Von to
solve the problems. The Load will start or stop sinking current when the UUT output voltage
reaches the Von voltage. You can start current loading when the load is ON, and the input
voltage is over Von voltage, but stop loading when the load is OFF, or the input voltage is
below Von voltage. See Figure 3-15 and Figure 3-16 for start and stop current loading.
There are two operation modes for Von control, latch and non-latch. Latch means that when
voltage is over Von voltage, Load will start current loading continuously in spite of the input
voltage drop is below Von voltage. Non-latch means that when the input voltage is below
Von voltage, the Load will stop current loading. The Von voltage and operation mode are set
in configuration.
Figure 3-15 Start Current Loading (Von Non-Latch)
Operation Overview
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