SUMMARYContrast to conventional dependent double-edge (DDE) pulse-width modulation (PWM), independent double-edge (IDE) PWM is investigated and applied to the control of switching dc-dc converters, with improved digital-peak-voltage (IDPV) controlled buck converter in this paper. IDE modulation unifies all the PWM schemes reported up to now and is thus called as unified PWM. It is revealed that conventional trailing-edge, leading-edge, trailing-triangle, and leading-triangle modulations are special cases of IDE modulation. The control laws of IDPV controlled buck converter with IDE modulation are investigated and compared with those of IDPV with DDE modulation. Their stabilities and robustness are analyzed subsequently. Digital implementation of the unified PWM is also carried out. Steady-state and transient performances of IDPV controlled buck converters with IDE modulation and DDE modulation are compared and verified by experimental results. It is concluded that steady-state and transient performances of IDPV with IDE are better than those of IDPV with DDE modulation.