Audio amplifier circuit of the Expo flowerpot speaker

The speaker is composed of audio power amplifier IC-8002 as the core. Its internal circuit structure, pin functions and typical application circuit are shown in the figure below. 8002 is an audio power amplifier that connects two OTL circuits in a bridge-type BTL mode. It uses SOP8 package, has a maximum output power of 2W (3Ω/5V), a minimum output of 1.2W, and an operating voltage of 3~5.5V. When used, only a few peripheral components can form an audio power amplifier circuit. It is suitable for portable or pocket electronic products powered by batteries or USB, and has been widely used.

As can be seen from the figure below, this circuit is actually basically the same as the typical application circuit of LM4890. The pin arrangement functions of 8002 are the same as those of LM4890. Therefore, as long as the packages of the two are the same or similar, they can be directly interchangeable. Of course, some electrical characteristics will be different, and some circuits will require minor changes.