Elec/CEng 499 Design Project           Supervisor : Panajotis Agathoklis

 

 

 

Description

How it Works

Test Results

How Does it Work?

 The SMA D-Class amplifier consists of both a linear, low power stage, and a digital, high power stage.  At lower output power (up to 2 Watts) the linear stage amplifies the signal on its own. Current sensing resistors at the output of the linear stage send a voltage signal to a Schmidt trigger in the digital stage (D-Stage). This trigger activates the D-Stage once the output power from the linear stage reaches 2 Watts. Once the D-Stage is activated the additional power is supplied from the D-Stage rather than the linear stage.

                                                                               (Click to Expand Images)

 The linear stage amplifying low power signals ensures that the amplified audio signal is free from crossover distortion (caused when the input signal changes polarity), which is a shortcoming in most D-Class amps. The D-Stage is highly efficient, and since it provides the output power when required, the overall amplifier exhibits better power efficiency (80 -85 %) than typical linear amplifiers.

 Please refer to the final report provided in the Documentation section for in depth information.