For example, suppose you want 5V 0.1A (=0.5W) and you have a power supply with 5V 2A (=10W, a very generous specification) output and another with 5V 0.2A (=1W) output at hand.
If both of them do not have price and size issues, can both be used?
First, let’s check the “load regulation” of the electrical specifications. For example, suppose the condition is “within the range of 10% to 100% of rated output”.For a 5V 2A power supply, 10% is 0.2A, so if the load uses only 5V 0.1A, it is outside the specified range.
The fact that the measurement condition is “10% to 100% load” suggests that some characteristics may have changed in the “0% to 10% load” range.
The following are possible behaviors at low loads:
-Higher output voltage at light loads
-Oscillation frequency decreases and ripple increases slightly.
-The oscillation frequency does not change, but the mode shifts to repeating oscillation and stop, and ripple noise increases a little at the time.
If the frequency changes, it is conceivable that the oscillation frequency will be in the audible range, so there may be cases where some countermeasures are required.
*the load change is taken up for the subject, there are cases that a “minimum load” is specified.
When selecting a converter, it is necessary to check the spec range and various functions of the converter.
● Output may vary depending on load changes (output voltage may be higher at light loads)