This is a 5VDC to 12VDC boost converter circuit built based LT1070. The LT?1070/LT1071 are monolithic high power switching regulators. They can be operated in all standard switching configurations including buck, boost, flyback, forward,inverting and “Cuk”. A high current, high efficiency switch is included on the die along with all oscillator, control and protection circuitry.
5VDC to 12VDC LT1070 Boost Converter circuit Reference: LT1070 datasheet