Abstract—A digital multi-bit sigma-delta controller is proposed to control a synchronous buck dc-dc converter over wide range of load currents and input voltages. A multi-bit sigma-delta modulator obtains the PWM control and makes the control loop. The output of the sigma-delta is used to control two paths power switches. An extra inductive path is used in parallel with main inductor to improve the converter dynamic. The proposed method has been simulated at the behavioral level using MATLAB and SIMULINK environment. Simulation results show that the proposed method have better dynamic response and low power consumption over the conventional sigma-delta controllers.

Index Terms—Multi-bit, sigma-delta, PWM, SMPS, controller.

B. Abdi is with Damavand Branch, Islamic Azad University, Damavand,Tehran, Iran (e-mail: babakabdii@gmail.com).
T. Moosazadeh was with IC Design Laboratory, Department of Electrical Engineering, Amirkabir University of Technology, Tehran, Iran (e-mail:tmoosazadeh@aut.ac.ir)
J. S. Moghani is with the Electrical Engineering Department, University of Amirkabir University of Technology, Tehran, Iran (e-mail:moghani@aut.ac.ir).

Cite: B. Abdi, T. Moosazadeh, and J. S. Moghani, "Digital Multi-Bit Sigma-Delta Controller for Synchronous Buck DC-DC Converter," International Journal of Computer and Electrical Engineering vol. 4, no. 6, pp. 878-881, 2012.