A Low-Distortion High-Efficiency Class-D Audio Amplifier Based on Sliding Mode Control

Carrier-Based Double Integral Sliding-Mode Controller of Class-D Amplifier

“…The Ackermann's formula [14] is adopted here for an easy selection of sliding coefficients γ 1 , γ 2 , and γ 3 in terms of controller bandwidth f b . In order to have three real and repeated roots of the third-order polynomial in (13), it is assumed that…”

“…The employment of the hysteretic modulator (HM) based SMC is commonly retarded by three major concerns: the variable switching frequency as it lacks synchronization clock, vulnerable to high-frequency noise because of a differentiator, and lacking the ability to mitigate steady-state error [12]. An integral sliding-mode controller (ISMC) was proposed to overcome the latter two limitations by using an additional integral term of the error in the switching function [13]. An ISMC for a class-D amplifier using a hysteretic comparator generates an error signal e which is the controller's input signal by comparing the output voltage to a time-varying reference signal v ref .…”

Design of Novel Low-Power and High-Efficiency Class-d Audio Amplifier

“…So, the fullbridge configuration is suitable for class-D amplifier. Figure 7 shows a simple full-bridge configuration [16]. As it is shown in Figure 7, in full-bridge configuration, two MOSFETs are in on-state, for example A 1 and B 2 , and the other MOSFETs are in off-state, A 2 and B 1 [15].…”

“…To control the MOSFETs, a circuit called MOSFET's driver is needed. This circuit must be designed based on the MOSFET's characteristics such as MOSFET's gate capacitance (C g ) or Drain Source resistance (r ds ) [16].…”

“…However, unwanted harmonic in this method is lower than the PWM method [6]. Several methods and structures have been proposed to increase the efficiency of class-D amplifiers based on its stages [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21].…”