Demonstration circuit 621 is a 1.25MHz triple DC/DC switching converter using the LT1941. The LT1941 features fast switching speed, three internal power switches, and a wide input voltage range, making it a versatile and powerful IC that fits easily into spaceconstrained applications and removes the need for three separate DC/DC converters in triple output applications. The constant 1.1MHz switching frequency allows for the use of tiny, surface mount external components. The current-mode control topology yields fast transient response and good loop stability, requiring a minimum number of external compensation components and allowing the use of ceramic input and output capacitors. The anti-phase switching and single-IC solution reduces the input capacitance requirements from three separate capacitors to only two. The low resistance internal power switches maintain high efficiencies (typically 80% to 85%) over a wide range of input voltages and loads. Its 260µA shutdown current (activated by grounding all three of the RUN/SS pins) extends battery life. All three outputs have external adjustable soft-start capacitors to limit inrush current during turn-on. The wide VIN range of the LT1941 allows step-down, SEPIC, and boost configurations with up to 25V input. Power good terminals provide diagnostics for each output voltage (within 10% of final value) and the input voltage (within 10% of 5V and 12V). This board is designed for applications that require three outputs (two step-down supplies and a SEPIC or boost) with high load current in a small board space with low cost and low parts count as well as simple circuit design. The high current, on-board, triple monolithic switches eliminate the need for external switches. The use of ceramic capacitors in this circuit not only demonstrates small size and low cost, but the advantage of current-mode control in step-down, SEPIC, and boost applications with a simple compensation network for good stability and transient response. For optional adjustments in the output voltage, compensation, ripple, power good diagnostics, run/soft-start, and other aspects of LT1941 design, please consult the datasheet. With three outputs and internal power switches, this design can start to heat up under maximum load current and high ambient temperature conditions. Please consult the datasheet for thermal considerations, especially when altering the output voltage for much higher power DC/DC converters. Design files for this circuit board are available.