The MSK 5042 is a high efficiency, 4 amp, surface mount switching regulator. Output voltage is user adjustable through the use of two external resistors or one external potentiometer. Output voltages from 1.2 volts to 5.5 volts are possible. The operating frequency of the MSK 5042 is 300KHz and is internally set. An external "soft start" capacitor allows the user to control how quickly the output comes up to regulation voltage after the application of an input. An extremely low quiescent current of typically less than 2.5mA and nearly 95% operating efficiency at 5 volts out, keep the total internal power dissipation of the MSK 5042 down to an absolute minimum.