UNLESS OTHERWISE NOTED, this document contains PRODUCTION DATA.
The duty cycle of the buck converter operating in PWM mode is given as D = VOUT/VIN. The duty cycle increases as the input voltage comes close to the output voltage. In 100% duty cycle mode, it keeps the high side switch on continuously. The high side switch stays turned on as long as the output voltage is below the internal set point. This allows the conversion of small input to output voltage differences.