A novel method of improving the dynamic response of DC-DC converter

As communication power supply which has low output voltage, large load current, a good dynamic character is very important. The dynamic response character of DC-DC converter is effected by the controller, DC/DC converter, output filter and the parasitic parameters from the devices under the external disturbance such as a drastic load change. It´s not easy in the normal topology to realize a rapid dynamic response under the situation of a very short response time. Many studies about the switching frequency, the design of the controller or the effects of circuit parasitic components have been carried out. But the dynamic response character is not satisfying if high performance is needed. A novel method is presented in this paper. A separate compensation circuit can be applied. The operation principle of the circuit is analyzed. The simulation results under the condition of PI and PID controller, with or without the external compensation circuit are given. In order to verify the theory analysis and simulation, a prototype converter is built. The experimental results show that the circuit can effectively reduce the output drop and shorten the dynamic response time. The dynamic response character can be improved obviously. The presented method is feasible.