Method and apparatus for switched capacitor and inductor based-switch mode power supply

• US 10,084,384 B1
• Filed: 04/22/2015
• Issued: 09/25/2018
• Est. Priority Date: 04/22/2015
• Status: Active Grant

• Current Assignee: Sridhar Kotikalapoodi
• Original Assignee: Sridhar Kotikalapoodi
• Inventors: Kotikalapoodi, Sridhar
• Primary Examiner(s): Moody, Kyle J
• Assistant Examiner(s): Novak, Peter
• Application Number:
  US14/693,746
• Time in Patent Office: 1,252 Days
• CPC Class Codes: H02M 1/007 Plural converter units in cascade push-pull DC/DC converters with pre-regulator H02M3/3374; DC-AC converters following a DC-DC stage including a high frequency transformer H02M7/4807; DC-AC converters following a DC-DC conversion stage generating periodically varying voltages H02M7/4826
• CPC Class Codes: H02M 1/0095 Hybrid converter topologies, e.g. NPC mixed with flying capacitor, thyristor converter mixed with MMC or charge pump mixed with buck
• CPC Class Codes: H02M 3/07 using capacitors charged and discharged alternately by semiconductor devices with control electrode , e.g. charge pumps
• CPC Class Codes: H02M 3/158 including plural semiconductor devices as final control devices for a single load
• CPC Class Codes: H02M 3/1588 comprising at least one synchronous rectifier element H02M3/1582, H02M3/1584 take precedence

Abstract

Method and Apparatus for a switch mode power supply are disclosed. The switch mode power supply is efficient and generates a very small inductor current ripple and output voltage ripple. The switch mode power supply has a wider bandwidth and the filter components including magnetic storage element and the output capacitor can be made extremely smaller.

Claims

1. A power supply comprising:

a switched capacitor array consisting of switches and capacitors, wherein each of said switches has an ON state and an OFF state;

a first terminal of said switched capacitor array coupled to a first terminal of a magnetic storage element;

a second terminal of said switched capacitor array coupled to a first voltage;

a third terminal of said switched capacitor array coupled to a second voltage;

wherein said switched capacitor array consists of a first set of N switches connected in series between said first terminal of said switched capacitor array and said second terminal of said switched capacitor array and a second set of N switches connected in series between said first terminal of said switched capacitor array and said third terminal of said switched capacitor array;

wherein said switching capacitor array consists of N−

1 capacitors;

wherein N is greater or equal to 3;

wherein when there is a current flow in any of said capacitors in said switched capacitor array, said current flow is similar in magnitude to a current flow in said magnetic storage element;

wherein said switched capacitor array provides N similar phases in a switching clock cycle at said first terminal of said switched capacitor array wherein each phase of said N similar phases consists of a charging voltage which causes said current flowing through said magnetic storage element to increase and a discharging voltage which causes said current flowing through said magnetic storage element to decrease;

wherein said charging voltage is similar in magnitude in each of said N similar phases and said discharging voltage is similar in magnitude in each of said N similar phases; and

wherein, when said charging voltage is not equal to said first voltage at said second terminal of said switched capacitor array and said discharging voltage is not equal to said second voltage at said third terminal of said switched capacitor array, a configuration of said switched capacitor array to generate said charging voltage is different in each of said N similar phases and a configuration of said switched capacitor array to generate said discharging voltage is different in each of said N similar phases.

2. The power supply of claim 1 wherein at least one of said charging voltage and said discharging voltage is a fraction of said first voltage on said second terminal of said switched capacitor array.

3. The power supply of claim 1 wherein said switched capacitor array is controlled by N signals, each of said N signals is shifted in time from a previous N signal by 1/N times a switching clock cycle period, and wherein said N signals control said ON state and said OFF state of said first set of N switches and said second set of N switches in said switched capacitor array and wherein said N signals also control regulation of an output voltage of said power supply and voltages on said N−

1 capacitors.

4. A power supply comprising:

a switched capacitor array consisting of switches and capacitors, wherein each of said switches has an ON state and an OFF state;

a first terminal of said switched capacitor array coupled to a first terminal of a magnetic storage element;

a second terminal of said switched capacitor array coupled to a first voltage;

a third terminal of said switched capacitor array coupled to a second voltage;

wherein said switched capacitor array consists of a first set of N switches connected in series between said first terminal of said switched capacitor array and said second terminal of said switched capacitor array and a second set of N switches connected in series between said first terminal of said switched capacitor array and said third terminal of said switched capacitor array;

wherein said switching capacitor array consists of N−

1 capacitors;

wherein N is greater or equal to 3;

wherein when there is a current flow in any of said capacitors in said switched capacitor array, said current flow is similar in magnitude to a current flow in said magnetic storage element;

wherein said power supply is a step down converter;

wherein said second terminal of said switched capacitor array is coupled to an input of said power supply;

a second terminal of said magnetic element is coupled to an output of said power supply;

wherein said switched capacitor array provides N similar phases in a switching clock cycle at said first terminal of said switched capacitor array coupled to said first terminal of said magnetic storage element wherein each of said N similar phases consists of a charging voltage which causes said current flowing through said magnetic storage element to increase and a discharging voltage which causes said current flowing through said magnetic storage element to decrease;

wherein said charging voltage is similar in magnitude in each of said N similar phases and said discharging voltage is similar in magnitude in each of said N similar phases; and

wherein, when said charging voltage is not equal to said first voltage at said second terminal of said switched capacitor array and said discharging voltage is not equal to said second voltage at said third terminal of said switched capacitor array, a configuration of said switched capacitor array to generate said charging voltage is different in each of said N similar phases and a configuration of said switched capacitor array to generate said discharging voltage is different in each of said N similar phases.

5. The power supply of claim 4 wherein at least one of said charging voltage and said discharging voltage is a fraction of said first voltage.

6. The power supply of claim 5 wherein said switched capacitor array is controlled by N signals, each of said N signals is shifted in time from a previous one of said N signals by 1/N times one switching clock cycle period;

and

wherein said N signals control said ON state and said OFF state of said first set of N switches and said second set of N switches in said switched capacitor array and wherein said N signals also control a regulation of an output voltage of said power supply and a voltage on each of said N−

1 capacitors.

7. The power supply of claim 5 wherein N is equal to three and said switched capacitor array has two capacitors and a difference in voltage of said charging voltage on said magnetic storage element, which causes a current in said magnetic storage element to increase, and said discharging voltage on said magnetic storage element, which causes said current in said magnetic storage element to decrease, is proportional to ⅓

times said first voltage.

8. A power supply comprising:

a switched capacitor array consisting of switches and capacitors, wherein each of said switches has an ON state and an OFF state;

a first terminal of said switched capacitor array coupled to a first terminal of a magnetic storage element;

a second terminal of said switched capacitor array coupled to a first voltage;

a third terminal of said switched capacitor array coupled to a second voltage;

wherein said switched capacitor array consists of N switches connected in series between said first terminal of said switched capacitor array and said second terminal of said switched capacitor array and a second set of N switches connected in series between said first terminal of said switched capacitor array and said third terminal of said switched capacitor array;

wherein said switching capacitor array consists of N−

1 capacitors;

wherein N is greater or equal to 3;

wherein when there is a current flow in any of said capacitors in said switched capacitor array, said current flow is similar in magnitude to a current flow in said magnetic storage element;

wherein said power supply is a step up converter, wherein said second terminal of said switched capacitor array is coupled to an output of said step up converter, and wherein a second terminal of said magnetic element is coupled to an input of said power supply;

wherein said switched capacitor array provides N similar phases in a switching clock cycle at said first terminal of said switched capacitor array coupled to said first terminal of said magnetic storage element wherein each phase of said N similar phases consists of a charging voltage which causes said current flowing through said magnetic storage element to increase and a discharging voltage which causes said current flowing through said magnetic storage element to decrease;

wherein said charging voltage is similar in magnitude in each of said N similar phases and said discharging voltage is similar in magnitude in each of said N similar phases; and

wherein, when said charging voltage is not equal to said first voltage at said second terminal of said switched capacitor array and said discharging voltage is not equal to said second voltage at said third terminal of said switched capacitor array, a configuration of said switched capacitor array to generate said charging voltage is different in each of said N similar phases and a configuration of said switched capacitor array to generate said discharging voltage is different in each of said N similar phases.

9. The step up converter of claim 8 wherein at least one of said charging voltage and discharging voltage is a fraction of said first voltage.

10. The power supply of claim 9 wherein said switched capacitor array is controlled by N number of signals, each of said N number of signals being shifted in time from a previous N signal by 1/N times one switching clock cycle period, and wherein said N signals control said ON state and said OFF state of said first set of N switches and said second set of N switches in said switched capacitor array and wherein said N signals also control regulation of said first voltage and voltages on said N−

1 capacitors.

11. The power supply of claim 9 wherein N is equal to three and said switched capacitor array has two capacitors and a difference in voltage of said charging voltage on said magnetic storage element, which causes a current in said magnetic storage element to increase, and said discharging voltage on said magnetic storage element, which causes said current in said magnetic storage element to decrease, is proportional to ⅓

times said first voltage.