Patent ID: 8698476
Filing Date: 2014-04-15
Classification: H02M

Abstract:
1. A control circuit for a current mode controlled power converter including a switching regulator for converting an input voltage into an output voltage responsive to a control signal, the switching regulator having an inductor and at least one power switch connected to the inductor by a phase node, the control circuit comprising: a feedback circuit connected to the switching regulator, detecting the output voltage to generate a feedback signal; a compensation circuit connected to the feedback circuit, amplifying a difference between the feedback signal and a first reference voltage to generate an error signal; a current sense gain circuit connected to the switching regulator, detecting an inductor current of the inductor to generate a current sense signal; a ramp generator providing a ramp signal having a peak or a valley adjusted depending on one or more of an input voltage dependent signal, an output voltage dependent signal and a signal related to the voltage of the phase node; a modulator connected to the compensation circuit, the current sense gain circuit and the ramp generator, generating a modulation signal according to the error signal, the current sense signal and the ramp signal; and a driver connected to the modulator, generating the control signal responsive to the modulation signal to switch the at least one power switch, wherein the ramp generator comprises: a switch shunt to the capacitor and controlled by a clock to switch the capacitor to be charged or discharged; a voltage controlled voltage source controlled by a difference between two of the input voltage dependent signal, the output voltage dependent signal and the signal related to the voltage of the phase node to generate a differential voltage; and a voltage controlled current source connected to the capacitor and the voltage controlled voltage source, controlled by a difference between the differential voltage and a second reference voltage to provide a charge current for charging the capacitor to adjust the peak or valley of the ramp signal.