Hi barry,Go back and study some more. This is a DC-DC converter, NOT an amplifier. You apply an input voltage, and, depending on the model, you get a constant output voltage.
Study the datasheet: http://cds.linear.com/docs/Datasheet/1073fa.pdf
LT1073 is a DC-DC switching converter that can be configured for step up (boost) or step down (buck) conversion.
You can find formulae, circuits, explanations and all required information in the datasheet.
Here is the description from page 1 of the datasheet:
Hope this helps.
You can find the circuit on page 12.
The voltage is stepped up and provides a DC output of higher voltage than the input voltage with the help of the internal transistor, the inductor, (schottky) diode and the bulk capacitor. It operates as a boost converter.