Contents
What is the DC voltage after the LC filter?
Due to the PWM modulation of a class-D amplifier, a DC voltage of PVDD / 2 or half of the supply voltage is present after the LC filter. In SE mode, because the speaker is now ground-referenced, either a DC blocking capacitor or some other means of referencing the speaker to PVDD / 2 is necessary so that no DC voltage appears across the speaker.
Where to place LC filter in power supply?
Naturally, you’ll think of placing the LC filter between the output of the regulator and the load. While there’s nothing wrong with that placement, you can achieve better noise reduction by placing the LC filter at the input if you’re using a buck regulator.
Is the DC power supply a perfect line?
In an ideal world, the voltage from the output of a DC power supply is a perfect horizontal line when observed on an oscilloscope. However, the world is far from ideal and the voltage is never a perfect line. The DC power supply is susceptible to AC ripple and noise and even more so for a switching power regulator.
Why is LC filter important in amplifier design?
Proper component selection of the LC filter is critical to meet the desired audio performance, efficiency, EMC/EMI requirements, and cost for the end application. This application report serves as a guide to aid in the section of LC filter components for class-D amplifiers to meet target-design goals of the end system.
Do you need a filter in a Class D amplifier?
In higher-power class-D amplifiers, generally above 10 W of output power, a filter on the output of the amplifier is required. The filter is passive in nature and uses both an inductor and a capacitor on each output terminal.
How is a smoothing capacitor used in a power grid?
A smoothing capacitor reduces the residual ripple of a previously rectified voltage. This article describes the operation of a smoothing capacitor. In addition to the calculation formula, you will also find a practical online calculator for sizing the capacitor. The German power grid supplies a sinusoidal AC voltage with a frequency of 50 Hz.