This is a design circuit for the Maxim MAX756 is the sample of easy to use DC to DC step-up switching regulator; this chip is used to increase the typically low input DC voltage 1.1 volt - 1.8 volt to the output DC voltage of 3.3 Volt or 5 Volt at maximum 200mA load (300mA on 3.3 Volt output). This is the figure of the circuit;
This means you could easily power your microcontroller project using just a single AA/AAA battery. This kind of step-up power is widely use on digital and microcontroller circuit that powered by low input voltage battery such as micro alkaline 1.5 volt battery. The basic schematic for 5 volt output from 1.5 volt battery. The output voltage of Maxim MAX756 could be selected from 5 volt or 3.3 volt by putting logical low or high on pin 2 (3/5), it also supply the low output indicator detector to the circuit if needed through the pin 4 (LBO). The following picture shows the Maxim MAX756 IC circuit powering the microcontroller’s board using just 1 AA alkaline battery (1.5 Volt).
