3. Pulsewidth Modulated Switching
Power Supplies
21
Although pulsewidth modulated (PWM) switching power supplies have been
around for a long time, it wasn’t until the mid-1970s that they became more
accepted and broadly applied. Switching power supplies offer many advantages
over linear regulators.
Switching power supplies are more efficient and are smaller in size than linear
regulators of similar ratings. They are, however, more difficult to design and
radiate more electromagnetic interference (EMI).
Today, there are two ways to approach the design of switching power sup-
plies. The design of board-level, dc/dc (dc-in, dc-out) switching power supplies ...