Design and Implementation of On-Chip Voltage Regulation for Power Management in System-On-Chip

The digital PWM modulator circuit is capable of varying the duty cycle of the output (PWM) according to the digital input word. A digitally controlled current starved pulse width modulator is described. The current from the power grid to the ring oscillator is controlled by a header circuit. By changing the header current, the pulse width of the switching signal generated at the output of the ring oscillator is dynamically controlled, permitting the duty cycle to vary between 25% and 90%. A duty cycle to voltage converter is used to ensure the accuracy of the system under process, voltage and temperature (PVT) variations. A ring oscillator with two header circuits is proposed to control both duty cycle and frequency of the operation. Analytic closed form expressions for the operation of a PWM are provided. The proposed PWM is appropriate for dynamic voltage scaling systems due to the small onchip area and high accuracy under PVT variations. The header circuit controls the amount of current delivered to the pMOS transistors within the ring oscillator. This header circuit provides a high granularity duty cycle. It provides a duty cycle in constant frequency. Here digital to analog converter using digital pulse width modulator is designed. .