Digital controllers for pulse-width modulation (PWM) converters are enjoying growing popularity due to their low power, immunity to analog component variations, ease of integration with other digital systems, ability to implement sophisticated control schemes, and potentially faster design process [1].
We are developing IC implementations of digital controllers for power converters that find applications in areas such as microprocessor voltage regulation modules (VRM) [2,3] and mobile device power supplies. We explore various topologies for the modules contained in a digital controller in order to provide a high-performance, low-cost solution. We have developed a very low power digital PWM (DPWM) generation module, PID control modules, and a novel low power ADC which is insensitive to switching noise and partially synthesizable. In the past year, we implemented a digital controller system for cell phone application with on-chip power switches. Now we are working on a fast, low power ADC module, and completing a digital controller for microprocessor VRM.
Some modules we developed such as the partially synthesizable ADC might have broader applications in other designs that aim for low power and a moderate conversion frequency range.