The MPM3840 is a monolithic, step-down, switch-mode converter with built-in, internal power MOSFETs and an inductor. The MPM3840 can provide 4A of continuous output current from a 2.8V to 5.5V input voltage with excellent load and line regulation. The MPM3840 is ideal for powering portable equipment that run on a single-cell Lithium-ion (Li+) battery. The output voltage can be regulated as low as 0.6V. Only input capacitors, output capacitors, and feedback (FB) resistors are required to complete the design. The constant-on-time (COT) control scheme provides a fast transient response, high lightload efficiency, and easy loop stabilization. Full protection features include cyclebycycle current limiting and thermal shutdown. The MPM3840 requires a minimal number of readily available, standard, external components and is available in an ultra-small QFN-20 (3mmx5mmx1.6mm) package.