Buck Boost converter - part 2

DC to DC converters are important in portable electronic devices such as cellular phones and laptop computers which are supplied with power from batteries. Such electronic devices consists of sub-circuits with each sub-circuit requiring unique voltage levels different from that supplied by the batteries,sometimes higher,sometimes lower than the battery voltage,sometimes even negative voltage. Additionally, the battery voltage declines as its stored power is drained. DC to DC converters offer a method of generating multiple controlled voltages from a single variable battery voltage, thereby saving space instead of using multiple batteries to supply different parts of the device.