The MPQ2459 is a monolithic, step-down, switch-mode converter with a built-in power MOSFET. It achieves a 0.5A peak output current over a wide input-supply range with excellent load and line regulation. Current mode operation provides a fast transient response and eases loop stabilization. Fault protections include cycle­by­cycle current limiting and thermal shutdown. The MPQ2459 requires a minimal number of readily-available, standard, external components. The MPQ2459 is available in a TSOT23-6 package.