Spur-free current-mode hysteretic boost converter for noise-sensitive loads

A current-mode hysteretic boost converter with wide-band spread-spectrum control is introduced. The proposed converter produces a spur-free output spectrum under all operating conditions regardless of any variations in the switching frequency, load current or input and output voltages. Therefore, no additional passive filtering, or subsequent regulation is necessary to enable powering noise-sensitive loads from the converter. The proposed control scheme alleviates the need for complex frequency control loops that had been traditionally used with hysteretic converters to maintain a predictable noise spectrum. Simulation results demonstrate the successful operation of the proposed control scheme and the full elimination of output spurs.