The MPQ4431 is a frequency-programmable (350kHz to 2.5MHz), synchronous, step-down switching regulator with integrated, internal, high-side and low-side power MOSFETs. It provides up to 1A of highly efficient output current with current mode control for fast loop response. The wide 3.3V to 36V input range accommodates a variety of step-down applications in automotive input environments and is ideal for battery-powered applications due to its extremely low quiescent current. The MPQ4431 employs advanced asynchronous mode (AAM), which helps achieve high efficiency in light-load condition by scaling down the switching frequency to reduce switching and gate driving losses. Standard features include soft start (SS), external clock synchronization, enable (EN) control, and a power good (PG) indicator. High-duty cycle and low dropout mode are provided for automotive cold-crank condition. Over-current protection (OCP) with valley-current detection is employed to prevent the inductor current from running away. Hiccup mode reduces the average current in short-circuit condition greatly. Thermal shutdown provides reliable and fault-tolerant operation. The MPQ4431 is available in a QFN-16 (3mmx4mm) package.