The PAM8403 is an Amplifier Board that can be powered using simple 5V input and could drive two 3W + 3W stereo speakers. It is an excellent choice for, who wants a Class-D stereo audio amplifier in a small board space.
The IRFI740G is an N-Channel MOSFET from International Rectifier. It has maximum VDSS rated at 10V and can handle continuous drain current up to 5.4A at 150C. The IRFI740G is a 400V 5.4A 40W TO220F Plastic Package 3Pins Power MOSFET.
The FSDM0565R is an integrated Pulse Width Modulator (PWM) and Sense FET specifically designed for high performance offline Switch Mode Power Supplies (SMPS) with minimal external components TO-220F-6Pins Packge.