Digital PWM control implementation for System on Chip devices

Nowadays, PWM control circuits are usually embedded into a microprocessor or a system-on-chip core. It is up to designer´s choice to evaluate precisely the quantity of resources required for such an implementation and how much the control function and/or the power topology influence this decision. The paper proposes a method of evaluation for resource usage in case of different control functions for a PWM controlled switch power supply. Starting from the basic functional equations for a closed loop PWM controlled system, calculations and simulations steps can provide a solution for digital PWM implementation.