The microprocessor uses a linear regulator power circuit constructed as shown below, use two MAX666 simply. CPU and A / D converter power supply using A2, RAM and real-time clock power supply with A1. MAX666 output voltage Vo by the VSET (6 feet)
to control access if VSET GND, a fixed 5V output voltage. If the resistor for dividing Vo, voltage is applied to VSET terminal share, thereby programmable output.