Demonstration circuit 1046A is a non-isolated, high efficiency buck-boost DC/DC supply featuring LTC3780EG and LTC4440ES6. The LTC3780 is a high performance 4-switch synchronous buck boost regulator and the LTC4440 is a 100V-rated FET driver. The input voltage of the demo board is designed for 36V to 72V. The output voltage is 48V. At 25C° room temperature, the maximum output current is 5A without a cooling fan and 6A with 150LFM air flow for cooling. An optional 12V bias flyback supply using the LTC3803 is stuffed on the board to power the LTC3780 and LTC4440.