Mixed-mode power converter control

A controller for a power converter configured to generate an output voltage in response to a pulse-width modulation (PWM) control signal, the controller including:

• (a) an error amplifier configured to be coupled to a voltage representative of the output voltage of the power converter and to a target voltage, and to output a comparison signal indicative of a difference between the coupled voltages;
• (b) a current-controlled voltage source configured to be coupled to the power converter, and configured to output a modified comparison signal comprising a combination of (1) a proportional voltage that is proportional to certain bandpass-limited frequencies of a representative current of the power converter, wherein the representative current is time-varying and the proportional voltage is only generated in significant amounts when a frequency of the time-varying representative current is within the certain bandpass-limited frequencies, and (2) the comparison signal output from the error amplifier;
• and
• (c) a comparator, having a first input coupled to the modified comparison signal and a second input configured to be coupled to a periodic voltage signal, configured to output the PWM control signal based on a comparison of the periodic voltage signal and the modified comparison signal.

A controller for a power converter controlled by a pulse-width modulation (PWM) control signal and configured to receive an input voltage VIN and generate an output voltage VOUT different from VIN, the controller including:

• (a) a comparison circuit configured to be coupled to a voltage representative of an output voltage of a power converter and to a target voltage, and to output a comparison signal indicative of a difference between the coupled voltages;
• (b) a modifier circuit configured to be coupled to the power converter, and configured to output a modified comparison signal comprising a combination of a voltage proportional to a representative current of the power converter and the comparison signal output from the comparison circuit, wherein the modifier circuit includes a bandpass filter configured to generate the voltage proportional to the representative current only for certain frequencies of the representative current;
• (c) a voltage generator configured to output a periodic voltage signal;
• and
• (d) a comparator, having a first input coupled to the modified comparison signal and a second input coupled to the voltage generator, configured to output the PWM control signal based on a comparison of the periodic voltage signal and the modified comparison signal.