Automotive batteries, industrial power supplies, distributed supplies and wall transformers are all sources of wide-ranging, high voltage inputs. The easiest way to step down the voltage from these sources is with a high voltage, monolithic step-down switching regulator that can directly accept a wide input range and produce a well-regulated output. This paper introduces the LT3680 and LT3693, two new step-down switching regulators that accept inputs up to 36V and provide excellent line and load regulations and dynamic response. Both regulators offer high efficiency solutions over wide load range. The LT3680 adds low ripple Burst Mode operation to maximize efficiency at light load currents.