Synchronization of multiphase synthetic ripple voltage regulator

In a multiphase DC-DC voltage converter having a controller, which generates a plurality of pulse width modulation (PWM) switching signals that switchably control operation of respective switching circuits containing first and second electronic power switching devices coupled between respective power supply terminals, and having phase nodes thereof coupled through inductors to multiphase regulated voltage output voltage terminals, the improvement comprising:

• a master clock waveform generator;
• an auxiliary voltage waveform generator which is operative to generate auxiliary voltage waveforms that effectively replicate ripple current waveforms through said inductors;
• and
• a control circuit that is operative to control the generation of said PWM switching signals in accordance with said master clock waveform and respective ones of said auxiliary voltage waveforms.

A multiphase synthetic ripple voltage regulator for a multiphase DC-DC converter, said multiphase synthetic regulator generating a plurality of pulse width modulation (PWM) switching signals that switchably control operation of respective switching circuits containing first and second electronic power switching devices coupled between respective power supply terminals, and having phase nodes thereof coupled through inductors to multiphase regulated voltage output voltage terminals, said multiphase synthetic ripple voltage regulator comprising:

• a master ripple voltage generator which is operative to generate a master ripple voltage waveform in accordance with respective currents proportional to the difference between an output voltage of said regulator and one of an input voltage or ground;
• a hysteretic comparator which is operative to generate a master clock waveform in accordance with prescribed relationships between said master ripple voltage waveform and upper and lower voltage thresholds;
• and
• PWM latch circuits, states of which define durations of respective components of a multiphase synthesized ripple voltage, a respective PWM latch circuit being coupled to have a first state thereof initiated by a selected master clock signal, and a second state thereof defined by an associated phase voltage comparator that monitors a respective phase node voltage.

A multiphase synthetic ripple voltage regulator for a multiphase DC-DC voltage converter, said multiphase synthetic voltage regulator generating a plurality of pulse width modulation (PWM) switching signals that switchably control operation of respective switching circuits containing first and second electronic power switching devices coupled between respective power supply terminals, and having phase nodes thereof coupled through inductors to multiphase regulated voltage output voltage terminals, said multiphase synthetic ripple voltage regulator comprising:

• a master ripple voltage generator which is operative to generate a master ripple voltage waveform having a first waveform portion defined in accordance with a first current proportional to the difference between an input and output voltage of said regulator, and having a second waveform portion defined in accordance with a second current proportional to the difference between ground and said output voltage;
• a hysteretic comparator which is operative to generate a master clock waveform in accordance with said first portion of said master ripple voltage waveform reaching an upper voltage threshold, and said second portion of said master ripple voltage reaching a lower voltage threshold;
• a plurality of phase ripple voltage generators, a respective one of which is operative to generate a respective phase ripple voltage waveform defined in accordance with a current proportional to the difference between an associated phase node voltage and said output voltage of said regulator;
• and
• a plurality of PWM latch circuits, states of which define durations of respective components of a multiphase synthesized ripple voltage, a respective PWM latch circuit being coupled to have a first state thereof initiated by a selected master clock signal, and a second state thereof defined by an associated phase voltage comparator that monitors a respective phase ripple voltage.