In the application note the reader can read things regarding signal, the rotational speed, serial data, wire interface, and hall sensor. Many things about flowchart, the ambient temperature, microcontroller, interface, and sensor signal are presented inside the application note.
This application note contains explanation regarding universal serial interface, the hall sensor, controller, the fan controller, and speed. Here are some excerpt from the application note:
AVR441: Intelligent BLDC Fan Controller with Temperature Sensor and Serial Interface Features • Application Example for Controlling Brushless DC Motors – Ideal for Use as an Integrated Fan Controller • Automatically Adjusts Fan Speed According to Chip Temperature • Automatically Detects Fan Failures • Two-Wire Interface for Remote Control and Monitoring 1 Introduction 8-bit Microcontrollers Application Note As package dimensions go down and power consumption figures goes up thermal management becomes an increasingly important factor in modern day electronics design.
Giving more content, this application note presents more things like sensor, controllers, serial interface, implementation, and calibration.