Demonstration circuit 1225 is high efficiency nonisolated SEPIC (Single Ended Primary Inductor Converter) converter featuring the LTC1871-1 switching controller. The DC1225 converts 5V to 20V input to 12V output and provides over 3A of output current. The converter operates at 300kHz with efficiency over 94%. With proper amount of airflow, the DC1225 converter can generate over 3A of output current. The DC1225 can be easily modified to generate output voltages in the range from 1.23V to 48V. Also, the DC1225 can be modified for other input voltages like 5V-36V, 9V-36V, 36V-72V, and so on. The wider input voltage range will decrease the converter efficiency.