+ He V hezkz17 into the research and development of digital audio system Q & A group (research group)
The class D amplifier works in the switch state, the transistor itself as the control element consumes less power, and the efficiency of the power amplifier
is high, which can reach more than 90%, so it can greatly reduce energy consumption and reduce the size of the amplifier. Compared with traditional analog power amplifiers, Class D audio
power amplifiers have broader development prospects.
Class D power amplifier is an amplification mode in which the amplifying element is in a switching state. When there is no signal input, the amplifier is in the cut-off state and does not consume power. When working, the transistor enters a saturated state by the input signal, and the transistor is equivalent to a switch that is turned on, directly connecting the power supply and the load. Ideal transistors do not consume power because they have no saturation voltage drop. In fact, transistors always have a small saturation voltage drop and consume part of the power. This kind of power consumption is only related to the characteristics of the tube, but has nothing to do with the size of the signal output, so it is especially beneficial to the occasion of super high power. Under ideal conditions, the efficiency of class D power amplifier is 100%, the efficiency of class B power amplifier is 78.5%, and the efficiency of class A power amplifier is only 50% or 25% (depending on the load mode). The point is that the output to the rear stage of the speaker is a switching signal (digital signal).
(1) Analog input, digital output class D power amplifier chip
(2) I2S digital input, digital output class D power amplifier chip
