New Digital Control Architecture Eliminating the Need for High Resolution DPWM

Due to the non-linear quantization effects of A/D converter and digital pulse-width modulator (DPWM), limit cycle oscillation is hard to predict in the voltage-mode digital controlled switching power supplies. As a result, one dedicated DPWM with very high resolution is indispensable to reduce the limit cycle oscillations, which usually results complexity and high cost for digital controllers. This paper investigates a new digital control architecture eliminating the needs for high resolution DPWM, so that greatly cost reduction can be achieved. Experimental verification is done at the hardware prototype to verify the control concept.