This post explains for the Audio Amplifier.
The Part Number is MC4863.
The function of this semiconductor is Dual 2.2W Audio Amplifier Plus Stereo Headphone Function.
Preview images :
The MC4863 is a dual bridge-connected audio power amplifier which, when connected to a 5V supply, will deliver 2.2W to a 4 Ω load(No t e 1) or 2.5W to a 3 Ω load(No t e 2) with less than 1.0% THD+N. In addition, the headphone input pin allows the amplifiers to operate in single-ended mode to drive stereo headphones. Boomer audio power amplifiers were designed specifically to provide high quality output power from a surface mount package while requiring few external components,to simplify audio system design, it combines dual bridge speaker amplifiers and stereo headphone amplifiers on one chip. The MC4863 features an externally controlled, low-power consumption shutdown mode, a stereo headphone amplifier mode, and thermal shutdown protection. It also utilizes circuitry to reduce “clicks and pops” during device turn-on. […]
1. Stereo headphone amplifier mode
2. “Click and pop” suppression circuitry
3. Unity-gain stable
4. Thermal shutdown protection circuitry
1. Multimedia monitors
2. Portable and desktop computers
3. Portable televisions