The MAX618 CMOS, PWM, step-up DC-DC converter generates output voltages up to 28V and accepts inputs from +3V to +28V. An internal 2A, 0.3 switch eliminates the need for external power MOSFETs while supplying output currents up to 500mA or more. A PWM control scheme combined with Idle ModeTM operation at light loads minimizes noise and ripple while maximizing efficiency over a wide load range. No-load operating current is 500A, which allows efficiency up to 93%.