Demonstration circuit 527 is a monolithic step-up / stepdown DC/DC switching converter with Burst Mode™ featuring the LT3433. The board is optimized for 5V output at up to 400mA load current (12VIN) and an input voltage range of 4V to 60V. With its wide input voltage range, 500mA internal power switches, 100μA quiescent current during Burst Mode, 200kHz switching frequency and thermally enhanced package, the LT3433 is a very versatile and powerful IC for DC/DC converters that require both step-up and step-down capability for 5VOUT as well as compact space, high efficiency, low cost, and tolerance to high input voltage transients. The LT3433 200kHz switching frequency allows all of the components to be small, surface mount devices. The current-mode control topology creates fast transient response and good loop stability with a minimum number of external components. The SHDN pin can be used to program undervoltage lockout or place the part in micropower shutdown, reducing supply current to 10μA (25μA maximum) by driving the pin low. Burst Mode operation is jumper selectable for extremely low, light load quiescent current. The LT3433 datasheet gives a complete of the part, operation and applications information. The datasheet must be read in conjunction with this Quick Start Guide for demonstration circuit 527. The LT3433 is assembled in a small 16-pin thermally enhanced package with exposed pad. Proper board layout is essential for maximum thermal performance.