Buck (or boost) converter with very fast output current transitions and low ripple voltage

A method of inducing very fast transitions of output current in a buck converter of the type comprising an n-phase buck converter (where n is an integer greater than one) operating at a switching frequency f for converting power from a voltage source having a voltage output and a voltage return to an output load having a load input and a load return, the load return being connected to the voltage return of the voltage source, and having zero output ripple comprising

• a quantity n of buck converter sections, each of the n buck converter sections comprising
• an inductor having a first winding a first terminal and a second terminal and a second winding having a first terminal and a second terminal, the first terminal of the at least a first winding having the same phase as the first terminal of the second winding
• an input switch connecting the voltage output of the voltage source to the first terminal of the at least a first winding of the inductor during the time that the input switch is closed,
• and a catch switch connecting the first terminal of the at least a first winding of the inductor to the voltage return of the voltage source during the time that the catch switch is closed,
• the input switch and the catch switch being constrained such that one and only one of the input switch and the catch switch is closed at any instant of time,
• and an output capacitor having a first terminal connected to all of the n second terminals of the at least a first windings of the n inductors and to the load input of the output load, and the output capacitor having a second terminal connected to the voltage return of the voltage source,
• wherein the second windings of the n inductors are connected in series such that the second terminal of each of the n inductors connects to the first terminal of the next of the n inductors in succession until all of the second windings of the n inductors are connected in a continuous series circuit,
• wherein, at any instant of time during quiescent operation, a quantity m of the n input switches is closed (where m is an integer greater than one and less than n),
• wherein a switching period P is defined as the reciprocal of the switching frequency f,
• wherein each of the n input switches has the same duty cycle D where D is defined as the ratio of the time that the input switch is closed to the switching period P, and
• wherein D is equal to the ratio of m to n,
• the method comprising
• suspending quiescent operation by inserting a period of time where at least m plus one of the n input switches is closed to increase rapidly the output current, and
• suspending quiescent operation by inserting a period of time where no more than m minus one of the n input switches is closed to decrease rapidly the output current.

A method of inducing very fast transitions of output current in a buck converter of the type comprising an n-phase buck converter (where n is an integer greater than one) operating at a switching frequency f for converting power from a voltage source having a voltage output and a voltage return to an output load having a load input and a load return, the load return being connected to the voltage return of the voltage source, and having zero output ripple comprising

• a quantity n of buck converter sections, each of the n buck converter sections comprising
• an inductor having a first winding a first terminal and a second terminal and a second winding having a first terminal and a second terminal, the first terminal of the at least a first winding having the same phase as the first terminal of the second winding
• an input switch connecting the voltage output of the voltage source to the first terminal of the at least a first winding of the inductor during the time that the input switch is closed,
• and a catch switch connecting the first terminal of the at least a first winding of the inductor to the voltage return of the voltage source during the time that the catch switch is closed,
• the input switch and the catch switch being constrained such that one and only one of the input switch and the catch switch is closed at any instant of time,
• and an output capacitor having a first terminal connected to all of the n second terminals of the at least a first windings of the n inductors and to the load input of the output load, and the output capacitor having a second terminal connected to the voltage return of the voltage source,
• wherein the second windings of the n inductors are connected in series such that the second terminal of each of the n inductors connects to the first terminal of the next of the n inductors in succession until all of the second windings of the n inductors are connected in a continuous series circuit,
• wherein, at any instant of time during quiescent operation, a quantity m of the n input switches is closed (where m is an integer greater than one and less than n),
• wherein a switching period P is defined as the reciprocal of the switching frequency f,
• wherein each of the n input switches has the same duty cycle D where D is defined as the ratio of the time that the input switch is closed to the switching period P, and
• wherein D is equal to the ratio of m to n, and
• further comprising a control voltage injection means that is connected in series within the continuous series circuit of the n second windings of the n inductors for injecting at least one of a positive control voltage, zero control voltage and a negative control voltage,
• the method comprising
• injecting a positive control voltage into the continuous series circuit to increase rapidly the output current, and
• and injecting a negative control voltage into the continuous series circuit to decrease rapidly the output current.

A method of inducing fast transitions of output current in a buck converter of the type comprising an n-phase buck converter (where n is an integer greater than one) operating at a switching frequency f for converting power from a voltage source having a voltage output and a voltage return to an output load having a load input and a load return, the load return being connected to the voltage return of the voltage source, and having zero output ripple comprising

• a quantity n of buck converter sections, each of the n buck converter sections comprising
• an inductor having a first winding a first terminal and a second terminal and a second winding having a first terminal and a second terminal, the first terminal of the at least a first winding having the same phase as the first terminal of the second winding
• an input switch connecting the voltage output of the voltage source to the first terminal of the at least a first winding of the inductor during the time that the input switch is closed,
• and a catch switch connecting the first terminal of the at least a first winding of the inductor to the voltage return of the voltage source during the time that the catch switch is closed,
• the input switch and the catch switch being constrained such that one and only one of the input switch and the catch switch is closed at any instant of time,
• and an output capacitor having a first terminal connected to all of the n second terminals of the at least a first windings of the n inductors and to the load input of the output load, and the output capacitor having a second terminal connected to the voltage return of the voltage source,
• wherein the second windings of the n inductors are connected in series such that the second terminal of each of the n inductors connects to the first terminal of the next of the n inductors in succession until all of the second windings of the n inductors are connected in a continuous series circuit,
• wherein the voltage source is a controlled voltage source that is controlled to have a controlled voltage equal to Vi,
• wherein the buck converter has an output voltage that is equal to Vo,
• wherein, at any instant of time during quiescent operation, a quantity m of the n input switches is closed (where m is an integer greater than one and less than n),
• wherein a switching period P is defined as the reciprocal of the switching frequency f,
• wherein each of the n input switches has the same duty cycle D where D is defined as the ratio of the time that the input switch is closed to the switching period P,
• wherein D is equal to the ratio of m to n, and
• wherein during quiescent operation the controlled input voltage Vi is equal to the output voltage Vo divided by the ratio of n to m,
• the method comprising
• controlling the controlled input voltage to be greater than the output voltage Vo divided by the ratio of n to m to induce a fast increasing transition of the output current, and
• controlling the controlled input voltage to be less than the output voltage Vo divided by the ratio of n to m to induce a fast decreasing transition of the output current.