The MPQ2451 is a high frequency, step-down, switching regulator with an integrated high-voltage high-side power MOSFET. It efficiently provides up to a 0.6A output with current-mode control for fast loop response. The wide 3.3V-to-36V input range accommodates a variety of automotive step-down applications, and the 3µA shutdown-mode quiescent current allows use in battery-powered applications. The MPQ2451 achieves high power-conversion efficiency over a wide load range by scaling down the switching frequency under light-load condition to reduce the switching and gate driving losses. Frequency fold-back prevents inductor current runaway during start-up. Thermal shutdown provides reliable, fault-tolerant operation. The MPQ2451 is available in a cost-effective SOT23-6L, TSOT23-6L and QFN-6L packages.