The TPS5401 device is a 42-V, 0.5-A, step-down regulator with an integrated high-side MOSFET. Current-mode control provides simple external compensation and flexible component selection. A low-ripple pulse-skip mode reduces the supply current to 116 µA when outputting regulated voltage with no load. Using the enable pin, shutdown supply current is reduced to 1.3 µA when the enable pin is low. Undervoltage lockout is internally set at 2.5 V, but can be increased using the enable pin. The output voltage start-up ramp is controlled by the slow-start pin that can also be configured for sequencing/tracking. An open-drain power-good signal indicates the output is within 94% to 107% of its nominal voltage. A wide switching-frequency range allows efficiency and external component size optimization. Frequency foldback and thermal shutdown protect the part during an overload condition. The TPS5401 is available in a 10-pin thermally enhanced MSOP PowerPAD package.