Power regulation for large transient loads

• US 20100244788A1
• Filed: 03/25/2009
• Published: 09/30/2010
• Est. Priority Date: 03/25/2009
• Status: Active Grant

• Current Assignee: Silergy Semiconductor Technology (Hangzhou) Ltd. (Silergy Corporation)
• Original Assignee: Silergy Technology (Silergy Corporation)
• Inventors: Chen, Wei
• Granted Patent: US 8,138,731 B2
• Time in Patent Office: Days
• US Class Current: 323/234
• CPC Class Codes: H02M 3/1584 with a plurality of power processing stages connected in parallel

Abstract

Methods and circuits for power supply arrangement and control are disclosed herein. In one embodiment, a power supply can include: (i) an input capacitor coupled to an input terminal that is coupled to a power source, where the power source provides power that is constrained by a predetermined limit; (ii) an output capacitor coupled to an output terminal that is coupled to a load, where the load has a first load condition or a second load condition; (iii) a first regulator to convert an input voltage at the input terminal to an output voltage at the output terminal to power the load; (iv) a second regulator coupled to the first regulator; and (v) an energy storage element coupled to the second regulator, where the second regulator delivers energy from the energy storage element to the first regulator to maintain regulation of an output voltage at the output terminal when in the second load condition.

Claims

1. A power supply, comprising:

a) an input capacitor coupled to an input terminal, said input terminal being coupled to a power source, said power source providing power that is constrained by a predetermined limit;

b) an output capacitor coupled to an output terminal, said output terminal being coupled to a load, wherein said load has a first load condition or a second load condition;

c) a first regulator configured to convert an input voltage at said input terminal to an output voltage at said output terminal to power said load;

d) a second regulator coupled to said first regulator; and

e) an energy storage element coupled to said second regulator, wherein said second regulator is configured to deliver energy from said energy storage element to said first regulator to maintain regulation of an output voltage at said output terminal when in said second load condition.

2. The power supply of claim 1, wherein said predetermined limit of said power source is variable based on an operating condition of said power source.

3. The power supply of claim 1, wherein said predetermined limit limits a current or a power provided from said power source.

4. The power supply of claim 3, wherein said second regulator is configured to charge said energy storage element when current or power drawn from said input terminal is below said predetermined limit.

5. The power supply of claim 1, wherein said second regulator is configured to deliver energy directly to said output terminal for regulating said output voltage together with said first regulator under said second load condition.

6. The power supply of claim 5, wherein said second regulator is configured to:

a) sense said output voltage at said output terminal; and

b) deliver energy from said energy storage element to said output terminal when said sensed output voltage is below a target regulation level.

7. The power supply of claim 1, wherein said second regulator is configured to deliver energy to said input terminal during said second load condition to prevent current or power at said input terminal from exceeding said predetermined limit of said power source.

8. The power supply of claim 7, wherein said second regulator is configured to:

a) sensing voltage conditions at said input terminal; and

b) deliver energy from said energy storage element to said input terminal when said sensed voltage indicates said second load condition.

9. The power supply of claim 7, wherein said second regulator is configured to:

a) sense voltage conditions at said output terminal; and

b) deliver energy from said energy storage element to said input terminal when said sensed voltage indicates said second load condition.

10. The power supply of claim 5, wherein said second regulator comprises a charging current limit circuit, said charging current limit circuit being configured to limit a maximum charging current into said energy storage element.

11. The power supply of claim 10, wherein said charging current limit circuit further limits said maximum charging current drawn from said input terminal when said power source at said input terminal is below said predetermined limit.

12. The power supply of claim 1, wherein said energy storage element is charged when current or power drawn from said power source at said input terminal is lower than said predetermined limit.

13. The power supply of claim 12, wherein said energy storage element is charged when energy stored in said energy storage element is below a preset threshold.

14. The power supply of claim 1, wherein said second load condition occurs when power drawn by said load at said output terminal exceeds said predetermined limit of said power source.

15. A method of converting a power source at an input terminal into a regulated output level at a load coupled to an output terminal, the method comprising:

a) regulating a voltage of said load directly from said power source using a first regulator;

b) determining whether said load is in a first load condition or a second load condition;

c) charging energy to an energy storage element during said first load condition; and

d) discharging energy from said energy storage element when in said second load condition for maintaining said regulated output level at said load, and for maintaining input current or power below a predetermined limit, said predetermined limit constraining power provided by said power source.

16. The method of claim 15, wherein said discharging energy stored in said energy storage element when in said second load condition comprises using a second regulator.

17. The method of claim 16, wherein said charging energy to said energy storage element comprises using said second regulator during said first load condition.

18. The method of claim 15, wherein said charging energy to said energy storage element when in said first load condition comprises using a third regulator, said third regulator being coupled between said first regulator and said energy storage element.

19. The method of claim 15, wherein said discharging energy from said energy storage element when in said second load condition comprises discharging said energy to said output terminal.

20. The method of claim 15, wherein said discharging energy from said energy storage element when in said second load condition comprises discharging said energy to said input terminal.