Linear amplifiers use transistors (MOSFET or similar) to increase the amplitude of an applied signal. Whatever signal is applied to the gate of the transistor is amplified but a constant factor called the amplifier gain. By contrast, a Class D amplifier is a type of amplifier which uses transistors as ON/OFF switches. The signal to be amplified is converted to a series of pulses through pulse width modulation (PWM). The pulses are amplified and converted back to an analog signal by passing through a low-pass filter comprised of inductors and capacitors.
The main advantage of Class D Amplifiers is that they can be designed to be more efficient than traditional linear amplifiers. CET Technology has developed a new series of inductors specifically for use with high power, high-efficiency Class D amplifiers. These inductors use a compact ferrite core made from a high saturation, low loss material, along with a flat wire for high-frequency operation. The enclosed shape of the core provides added shielding as well.
Sizes range from 15mmX17.5mmX19mm up to 20mmX23mmX23mm. Standard inductance values are 10, 22 and 33µH, but can be adjusted to any value up to about 100µH. Current ratings can be as high as 30ADC.