Power is one of the major considerations in portable, battery-powered applications because of battery life and heat. Since the Audio Power Amplifier (APA) is an important power dissipating building block used in end applications such as cellular telephones, notebook computers, Personal Data Assistants (PDAs), Compact Disc (CD) and Digital Video Disc (DVD) Players, it is worth gaining a clearer understanding of its limitations and ability to deliver power to a load. Once these limitations and abilities are clearly understood, one will be better equipped in determining important parameters such as output power and the resulting Output Sound Pressure Level (SPL) produced by a speaker, input power and the resulting power supply requirements, and package power dissipation and the resulting die junction temperature.

This application note quantifies each of these important parameters and provides supporting empirical data acquired using the TC4864 in the Bridge Tied Load (BTL) topology and the Single-Ended Capacitively Coupled Load (SECCL) topology.