Higher order slope compensation for fixed frequency current mode switching regulators

A current mode switching regulator for regulating an output voltage, said current mode switching regulator comprising:

• a switch;
• a controller coupled to said switch, said controller governing the operational state of said switch so as to control current flow to a load;
• and
• a slope compensation circuit;
• said slope compensation circuit including:
• a first summer circuit for receiving a clock signal and a reference signal as input signals, and for generating a linear signal as an output signal;
• a multiplier and integrator circuit for multiplying said linear signal with an input voltage signal, and integrating the result for generating a non-linear signal which varies based on a measured value of a current flowing within said switch;
• a second summer circuit for receiving a first voltage signal corresponding to said non-linear signal and a second voltage signal indicating the difference between an actual voltage level of said current mode switching regulator and the desired voltage level of said current mode switching regulator, and for generating a first output signal which represents the second voltage signal minus the first voltage signal;
• and
• a comparator for receiving the first output signal from said second summer as a first input, and said measured value of a current flowing within said switch regulator as a second input, and for generating a second output signal utilized to control current flow through said switch.

A method of generating a slope compensation signal for use in a current mode switching regulator, said method comprising the steps of:

• summing a clock signal and a reference signal so as to generate a linear ramp signal;
• multiplying said linear ramp signal with an input voltage signal so as to generate a scaled signal which varies based on a measured value of a current flowing within said current mode switching regulator;
• integrating the linear scaled signal with respect to time to generate a non-linear ramp signal;
• summing a first voltage signal corresponding to said non-linear signal and a second voltage signal indicating the difference between an actual voltage level of said current mode switching regulator and the desired voltage level of said current mode switching regulator so as to generate a first output signal which represents the second voltage signal minus the first voltage signal;
• and
• comparing the first output signal and said measured value of a current flowing within said current mode switching regulator, and generating a second output signal utilized to control current flow within said current mode switching regulator based on the result of said comparison.