Design of a Digital Pulse Frequency Mode for the DC-DC Converter

The classical model in digital DC-DC converter is digital pulse width mode (DPWM), but the digital pulse frequency mode (DPFM) is very important in DC-DC converter with light load. This paper presents the different application environments and the effect between the two modes. There are two common different DPFM structures analyzed in this paper. And a novel DPFM circuit is proposed, which needs only external clock, not affected by the duty cycle of the clock. The circuit and layout are designed with 0.13um CMOS technology. The simulation results of the circuit meet the requirements of design.