MIXED TYPE FREQUENCY COMPENSATING CIRCUIT AND CONTROL CIRCUIT HAVING THE SAME

摘要

A mixed-type frequency compensating circuit and a control circuit having the same are provided to compensate a frequency characteristic by amplifying an input voltage signal in a voltage mode and a current mode, respectively. A mixed-type frequency compensating circuit comprises an integral component sub-circuit of a voltage-amplifier-type frequency compensating circuit for amplifying a feedback voltage signal in a voltage mode and performing frequency compensation, and a proportional component sub-circuit of a transconductance-amplifier-type frequency compensating circuit(210b) for amplifying the feedback voltage signal in a current mode and performing frequency compensation. A pole frequency of the mixed-type frequency compensating circuit is mainly determined by the integral component sub-circuit of the voltage-amplifier-type frequency compensating circuit. A zero frequency of the mixed type frequency compensating circuit is mainly determined by the integral component sub-circuit of the voltage-amplifier-type frequency compensating circuit and the proportional component sub-circuit of the transconductance-amplifier-type frequency compensating circuit.