Design a SEPIC Converter

This article tells about what is a sepic converter, how to design it. A SEPIC (single ended primary inductor converter) is a non-isolated DC-DC converter which allows the output voltage to be greater than, less than, or equal to the input voltage,which seems to be similar like buck-Boost converter type, but SEPIC gives positive voltage at the output,whereas a buck boost converter gives negative voltage at the output.In buck-boost configaration output current is continuous, input current is discontinuous, whereas in SEPIC both output and input currents are continuous. Lets find out more in the following links.

for circuit operation:
http://en.wikipedia.org/wiki/SEPIC_converter

for designing sepic converter:
http://www.national.com/an/AN/AN-1484.pdf