In every article that deals with Class T amplifiers you will find it linked to Class D ones. The reason is simple. They are similar, but the difference between them is that Class T uses a Tripath chip. That is, these amps have an audio amplifier IC design officially registered by Tripath’s amplifier technologies. (Although, nowadays, there are similar products in the market.) In short, this kind of amplifier has control signals calculated by using either digital signal processing or fully analog techniques.
More on Class T vs Class D
Covered products tend to use a Class D amp, which produces a better performance than other Class D amplifier designs. The reason is they use unique methods which merge exclusive techniques to control pulse width modulation. This type of amp has real-time control of the switching frequency, and it depends on the input signal, and on the amplified output as well.
Some Characteristics of Class T Amps
Digital or Analog?
Class T amplifiers calculate their control signals by using digital signal processing as well as analog techniques. Currently, there are applications that use a loop that is similar to a higher-order delta-sigma or sigma-delta modulator that has an internal digital clock. This digital clock controls the sample comparator.
On Feedback
The user takes the feedback directly from the switching node. Plus, the higher-order loop offers higher loop gain at high audio frequencies that might also be conceivable in a conventional single-pole amp. Class T amplifiers have a signal processing circuit that contains a frequency selective network in a feedback loop. This is for noise shaping purposes. The sampling analog-to-digital converter in the feedback loop runs at a sampling frequency that works significantly better than the Nyquist frequency.
Traditional methods only use state feedback. You can employ the state feedback to combine the analog-to-digital converter with the constant feedback of the switching device output. In this case, you control the switching device by a sampling analog-to-digital converter. In turn, it produces a constant signal that feeds back to the original frequency to avoid noise and distortion.
