Why is the power-stage design important to Class D amplifier performance?
Advances in Class D controllers have resulted in sonic performance that surpasses Class AB. Although the power stage seems simple compared to the controller, it must equal the controller’s sonic performance and do so at significantly higher voltages and currents. What are the criteria for output-filter components in a Class D amplifier? At peak current, the inductor must maintain its inductance and not saturate. It must exhibit low magnetic and resistive losses. And, it often requires shielding. The filter capacitor must exhibit low losses and good temperature stability. Designers usually choose polyester or polypropylene capacitors for these traits. What is shoot through? How can I prevent it? Shoot through can occur when the half bridge changes state. Finite switch-transition times let the off-going switch’s conduction overlap slightly with the on-going switch’s conduction. During the overlap, current flows from one rail, through both devices, and to the opposite rail, reducing relia
