Method and circuitry for controlling duty cycle of an input signal towards a desired value comprising a sequence of at least two inverters arranged in series and feedback circuitry. A first inverter is arranged to receive the input signal and a last inverter is arranged to output a signal having the same frequency as the input signal. The output signal is an adjusted version of the input signal. The feedback circuitry is arranged to receive the output signal and comprises a comparing and supplying means. The comparing means compares the output signal with a reference signal indicative of a desired value and generates a feedback signal based on the comparison of the output and reference signal. The supplying means supplies the feedback signal to adjust operating conditions of at least one of the inverters, such that the duty cycle of the output signal is controlled towards the desired value.