The LM2596 is a commonly used popular step-down switching regulator IC. The adjustable version can take in input voltage from 4.5V to 40V and convert it to variable voltage sourcing upto of 3A of continues current.
The IRFZ44N is a N-channel MOSFET with a high drain current of 49A and low Rds value of 17.5 mΩ. It also has a low threshold voltage of 4V at which the MOSFET will start conducting. Hence it is commonly used with microcontrollers to drive with 5V.
Silicon Labs introduced a family of isolated analog amplifiers, voltage sensors and delta-sigma modulator (DSM) devices designed to provide accurate current and voltage measurement with very low drift across temperature.
LD1117 is a Positive Voltage Regulator with a very low Voltage drop across it. Based on the version of the IC the output voltage can vary between fixed voltages like 1.2V, 1.8V, 2.5V, 2.85V, 3.0V, 3.3V, 5.0V or can also be a variable voltage regulator.