In recent years, the demand for fast reference tracking speed converter in high-speed adaptive supply systems has been in great demand. Converters with fast dynamic response and accurate reference-tracking capability with negligible overshoots, undershoots and oscillations are essential. Current-mode control has been known to have faster response time than voltage-mode control. However, current-mode control with fixed zero compensation still suffers from slow and non-optimized dynamic response under different load current conditions. Problems of overshoots, undershoots and oscillations are inevitable....[ Read more ]

In recent years, the demand for fast reference tracking speed converter in high-speed adaptive supply systems has been in great demand. Converters with fast dynamic response and accurate reference-tracking capability with negligible overshoots, undershoots and oscillations are essential. Current-mode control has been known to have faster response time than voltage-mode control. However, current-mode control with fixed zero compensation still suffers from slow and non-optimized dynamic response under different load current conditions. Problems of overshoots, undershoots and oscillations are inevitable.

In this thesis, a new frequency compensation scheme called Dynamic Zero Compensation (DZC) is proposed. This scheme aims for optimizing the loop response, and hence improving the dynamic response of the converter by tracing the load-dependent pole with a dynamic zero. Therefore, the output voltage can precisely reach a desired level with different reference voltages during reference tracking.

The proposed frequency compensation scheme has been successfully implemented in AMS 0.35μm CMOS technology. Experimental results demonstrated that the proposed converter functions properly with output voltage from 1V to 2.8V and at switching frequencies ranging from 500kHz to 1MHz. Moreover, a faster reference tracking speed with trifling overshoots, undershoots and oscillations is achieved in this design, compared with a conventional current-mode control converter with fixed zero compensation.