Research Projects

The rapid scaling of ICs has led to increased power requirements in Application Processors (APs), necessitating energy-efficient performance for a prolonged battery lifetime. Dynamic voltage scaling (DVS) is an effective method for optimizing power-performance by dynamically adjusting power-supply voltage during runtime. To maintain throughput and minimize latency, a DC-DC converter must have a wide dynamic range, ultra-fast DVS tracking response, and superior load-transient response with an unprecedented load slew-rate of 1 A/ns. To achieve ultra-fast DVS tracking and superior load transient response, the converter needs to be operated at tens of MHz switching frequency. Adopting a fast control mechanism is crucial to minimize the converter's response time. Classical PWM control exhibits poor transient response but is stable over a wide output range. Current-mode hysteretic control offers fast-transient response but has finite response time due to the hysteresis band and variable switching frequency, making it difficult to fix input-output filters optimally. To mitigate the stringent transient requirements of modern APs, an ultra-fast control mechanism operating at a fixed switching frequency is needed. A reconfigurable auto-selection of current modes is crucial for covering a wide output range and maintaining transient response. A multiphase DC-DC converter with active-phase count is needed to increase high-power demand of APs but requires exploration to maintain superior transient response.