An Ultra-fast Control Strategy and Pre-current-balancing Measures Prepared for Rapid Transients in Constant On-time Controllers

The paper presents an ultra-fast control strategy during step-up transients in constant on-time (COT) controllers. This control strategy significantly improves the magnitude of undershoot over the traditional COT control method. In addition, the pre-current-balancing measures can quickly balance the current deviation caused by the high dynamic strategy without additional sampling circuits so that the current remains balanced during rapid load steps to avoid triggering overcurrent protection. The control strategy is tested on a 16-phase Buck converter, and the results show that it dramatically improves the undershoot and maintains the current balance.