Synchronous rectification in Linear Tech’s LT8610A and LT8610AB 3.5-A, 42-V, input-capable step-down switching regulators delivers efficiency up to 96%, while Burst Mode operation keeps quiescent current under 2.5 µA in no-load standby conditions. Internal 5-A switches supply up to 3.5 A of continuous output current to voltages down to 0.97 V. Minimum dropout voltage is 200 mV at 1 A under all conditions. Minimum on-time of 30 ns enables 2-MHz constant frequency switching from a 16-V input to 1.0-V output to enhance efficiency and avoid noise-sensitive frequency bands. The LT8610AB has higher efficiency than the LT8610A at very light loads (< 0.5 mA), but it does result in slightly higher output ripple. Packaging is a 16-lead, thermally enhanced MSOP. Automotive and industrial temperature versions are available.