Main Article Content
The problem considered in this paper is improving the dynamic response of DC-DC converter system with internal parameter uncertainties. The methodology of sliding mode control in existing works is based on Proportional Integral and Derivative Controller (PID).The present work addresses various issues on a unified approach for design and application of pulse-width modulation (PWM) based Digital Adaptive Sliding Mode (ASM) equivalent control technique to buck converter for mobile phones operating in continuous conduction mode (CCM) and discontinuous conduction mode (DCM). The controller is gain scheduled to monitor the output loading condition, and adaptively changes the control parameters to give optimal dynamic performance corresponding to any load variations. Further stability is analytically verified using Lyapunov stability criterion and system is proved to be globally asymptotically stable. Finally effectiveness of proposed method is verified by simulation and experiment. Stable steady state response with reduced ripple is obtained.