Application-specific instruction-set processor for control of multi-rail DC-DC converter systems

Conventional digital signal processor (DSP) based digital controllers are not specifically optimized for multi-rail DC-DC converter applications. A new application-specific instruction-set processor (ASIP) that overcomes the shortcomings of existing controllers has thus been designed, implemented, and evaluated. The proposed dual multiply-accumulate (MAC) architecture has been implemented using a field programmable gate array and verified in a closed-loop power converter system. The benefits of the proposed ASIP are illustrated through a comparison with a conventional single MAC processor architecture. Experimental results demonstrate improved output voltage transient response compared with existing DSP-based controllers when controlling multiple DC-DC converters. In the case of multiple converters that have a non-integer switching frequency ratio more significant improvements in transient response are obtained due to the processor's interrupt controller.