Novel variable integral gain control DC-DC converter without load current detecting

The purpose of this paper is to presents a new integral gain switchover method that has the unique hysteresis function in which the current sensor circuit is not required. In this paper, two kind of integral gain switchover method is indicated. One is the two-step switchover method having the rectangle hysteresis function. The other is slope switchover method having rectangular triangle hysteresis function. The both of proposed method can switch the integral gain without load current detecting. Therefore, good regulation characteristic is obtained in the both cases. However, the transient response of two-step switchover method having the rectangle hysteresis function is not good when the load step varies from the critical point to DCM. This issue is improved by using rectangular triangle hysteresis function. As the result, the convergence time of slope switchover method having rectangular triangle hysteresis function can be improved by up to 81.3% compared with integral gain fixed method.