The illustration provides below schemes 8V-60V to 12V Converter Circuit Diagram. It uses LT3433, an automatic step up and step down switching regulator IC with 4V to 60V input voltage which can be useful in automotive electronics using various wide input voltage range.
According to the LT3433 datasheet, this Automatic Step-Up and Step-Down Conversion device is a 200kHz fixed frequency current mode switching regulator using a single inductor which can be applied in applications such as wall adapter powered systems and battery power voltage buffering.
Read completely about Step Up/Step Down DC to DC Converter Circuit Diagram using LT3433 here in pdf archive (source: linear.com)