Abstract:
Class D amplifier encodes a reference signal to a pulse width modulated signal using a switching
circuit that contains MOSFETs. It works as a switch and consumes power on the lower side
whether it works in the saturation region or cutoff region. At higher order frequency, disturbance
and chattering effects arise and LC filter is used to overcome this issue. To avoid the chattering
effect, more stages are needed to flatten the response of the frequency and shooting effect.
Consequently, the circuit becomes complex and efficiency is degraded due to the addition of
more stages of low pass filter. In this case, the heat sink requirement gains significance.
MOSFETs exhibit better efficiency, while operating at high voltage, current, and frequency and
GaN MOSFET offers high electric breakdown than Si and SiC. Gallium nitride HEMT (High
Electron Mobility Transistor) becomes the potential candidate for WBG (wideband Gap) and low
noise impedance. The open-loop simulation of the non-linear fourth-order class D amplifier
shows the chattering, settling time, and THD issue. To settle down these issues sliding mode
controller (SMC) has been proposed to deal with the nonlinear model of the amplifier. SMC has
two major parts; one is sliding manifolds and the other is the control law. SMC is robust and
easy to implement on the higher-order system to linearize the model. Super twisting and dynamic
controllers are the best techniques of the SMC. The super twisting algorithm is a continuous SM
algorithm ensuring the main properties of the first order sliding mode control for systems with
Lipschitz continuous matched uncertainties or disturbances with bounded gradients. While the
dynamic sliding mode controller (DSMC) is worked with uncertainties, unknown parameters,
and disturbances. DSMC has the edge over other SMC techniques because it works for the
missing information parameters and converges the whole system. The chattering, noise,
shooting, and settling time issues are resolved by using the proposed control technique. The
proposed technique enhances the class D amplification more than super twisting sliding mode
controller (STSMC) and open loop. This proposed technique is applicable in artificial
intelligence vehicles, SONAR, RADAR and wind turbine systems.
