The HT878T is a stereo Class D audio amplifier that drives up to continuous 2×6.8W (1% THD+N, boosted to 8.3V) into 4ohm speaker. It also integrates Class AB amplifier to avoid EMI.
HT878T built-in Class G boost converter supports adjustable boost voltages. The boost converter is automatically active only when a higher audio output power is required, which will significantly improve the efficiency and extends the playing time in battery supply applications.
HT878T integrates Limiter function. When it is active, the output music can be limited below a certain power and THD+N. This will allow different demands in sound performance and prevent speakers from damage.
The Thermal Foldback (TFB) function is designed to protect the HT878T from excessive die temperature in case of the device being operated beyond the recommended temperature or power limit, or with a weaker thermal system than recommended. The TFB works by reducing the on-die power dissipation by reducing Gain if the temperature trig point is exceeded, so that the peak audio power is significantly increased.
HT878T has a filter-less modulation circuit which can directly drive speakers. HT878T can be shut down so that the power consumption can be minimized. As for protection function, over current protection function for speaker output terminals, over temperature protection function and low supply voltage malfunction preventing function are also prepared.