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Verification and Performance Tests 15
unloading transients by triggering on the positive and negative slope.
Figure 2-2. Transient Response Waveform
Constant Current (CC) Tests
CC Setup
Follow the general setup instructions in the Measurement Techniques paragraph and the specific instructions given in the
following paragraphs.
Current Programming/Readback Accuracy
This test verifies that the current programming and readback are within specification. The accuracy of the current
monitoring resistor is determined by the power coefficient (see Table 1-1).
1. Turn off the module and connect the current monitoring resistor directly across the output and a DVM across the
resistor. Refer to the "Current Monitoring Resistor" paragraph.
2. Turn on the module and program the output voltage to 5V and the current to zero.
3. Divide the voltage drop (DVM reading) across the current monitoring resistor by its resistance to convert to amps and
record this value as (Io). The actual current (Io) and the reading on the keyboard display should be within the limits
specified in the Performance Test Record Tables under CC PROGRAMMING @ 0 AMPS, for the particular model
being tested.
4. Program the output voltage to 5V and the current to full-scale (see Table 2-1).
5. Divide the voltage drop (DVM reading) across the current monitoring resistor by its resistance to convert to amps and
record this value as (Io). The actual current (Io) and the reading on the keyboard display should be within the limits
specified in the Performance Test Record Tables under CC PROGRAMMING @ FULL SCALE, for the particular
model being tested.
CC Load and Line Regulation
These tests (CC Load Effect and CC Source Effect given below) are tests of the dc regulation of the power module’s output
current. To insure that the values read are not the instantaneous measurement of the ac peaks of the output current ripple,
several dc measurements should be made and the average of these readings calculated.