Closed-loop Dual Comparator and Its Applications

As technologies are moving to be faster, smaller, and better, demands for a reliable oscillator design have been increasing. A novel oscillator design using a closed-loop dual comparator circuit (CLDC) has previously been proposed and proven as a good relaxation oscillator for high-performance future applications. In this paper, other configurations of the CLDC circuit will be investigated for voltage regulator and power supply controller applications. The simulation results confirm that CLDC as a controllable switched capacitor for voltage regulator application can provide precise regulation with a peak-to-peak voltage ripple of 5 mV. Furthermore, CLDC is also promising to be used as a voltage mode controller for buck converter and can achieve load regulation and line regulation of 0.00025 mV/mA and 0.0015, respectively. The proposed controller demonstrates a fast load transient response and low dropout voltage despite high variability in the input load. As a result, a lower cost and better performance on-chip voltage regulator can be realized to fulfill the needs of future power supply systems.