Input Protection for Vdd and Adc of uC.
If the Vdd of uC is 5V then the Zd1 and Zd2 are 5.1V, and R1 can be use as 0.22Ω/3W or 5W, if the Vdd of uC is 3.3V then the Zd1 and Zd2 are 3.6V, and R1 can be use as 0.1Ω/3W or 5W, the values of R1 will affecting the voltage of Vdd.
If the Vdd of uC is 5V then the Zd1 and Zd2 are 5.1V, and R1 can be use as 0.22Ω/3W or 5W, if the Vdd of uC is 3.3V then the Zd1 and Zd2 are 3.6V, and R1 can be use as 0.1Ω/3W or 5W, the values of R1 will affecting the voltage of Vdd.
