Granted Patent B2

US 9,654,009 · App. 14/575,682 · Granted May 16, 2017

Abstract

Claims (80)

1. A method, comprising:

determining a voltage at a node between a first switch and a second switch of a power converter;

adjusting a frequency of an oscillating signal based at least on the determined voltage, said adjusting comprising:

determining whether the determined voltage is greater than a previously-determined voltage of the node;

adjusting the frequency in the same direction as was performed during a previous cycle in response to determining that the determined voltage is greater than the previously-determined voltage of the node; and

adjusting the frequency in an opposite direction than was performed during the previous cycle in response to determining that the determined voltage is not greater than the previously-determined voltage of the node; and

generating a control signal based on the frequency-adjusted oscillating signal that causes the first switch to be enabled.

2. The method of claim 1 , wherein said determining the voltage at the node comprises:

determining that the first switch is to be enabled; and

determining the voltage in response to determining that the first switch is to be enabled.

3. The method of claim 1 , wherein an amount in which the frequency is adjusted is based on a difference between the determined voltage and the previously-determined voltage of the node.

4. The method of claim 1 , wherein the power converter is a buck converter.

5. The method of claim 1 , wherein said determining, said adjusting, and said generating are performed during a discontinuous current mode of the power converter.

6. The method of claim 2 , wherein determining that the first switch is to be enabled comprises:

monitoring a voltage of a third control signal configured to enable the first switch;

determining that the monitored voltage reaches a predetermined threshold; and

determining that the first switch is to be enabled in response to a determination that the monitored voltage reaches the predetermined threshold.

7. The method of claim 1 , wherein the control signal causes the first switch to be enabled when the control signal reaches a threshold voltage of the first switch.

8. A power converter, comprising:

a high-side switch;

a low-side switch;

a node coupled to the high-side switch and the low-side switch;

voltage sampling logic coupled to the node, the voltage sampling logic configured to sample a voltage at the node; and

adjustment logic configured to generate a first control signal that adjusts a frequency of an oscillating signal based at least on the sampled voltage, the frequency-adjusted oscillating signal being used to generate a second control signal that causes the high-side switch to be enabled, wherein the adjustment logic comprises:

first logic configured to determine whether the sampled voltage is greater than a previously-sampled voltage of the node;

second logic configured to set the first control signal in a manner that causes the frequency of the oscillating signal to be adjusted in the same direction as was performed during a previous cycle in response to a determination that the sampled voltage is greater than the previously-sampled voltage of the node; and

third logic configured to set the first control signal in a manner that causes the frequency of the oscillating signal to be adjusted in an opposite direction than was performed during the previous cycle in response to a determination that the sampled voltage is not greater than the previously-sampled voltage of the node.

9. The power converter of claim 8 , further comprising:

a programmable oscillator configured to receive the first control signal and adjust the frequency of the oscillating signal based on the first control signal.

10. The power converter of claim 8 , wherein the voltage sampling logic comprises:

fourth logic configured to determine that the high-side switch is to be enabled; and

fifth logic configured to sample the voltage in response to a determination that the high-side switch is to be enabled.

11. The power converter of claim 10 , wherein the fourth logic comprises:

sixth logic configured to monitor a voltage of a third control signal configured to enable the high-side switch;

seventh logic configured to determine that the monitored voltage reaches a predetermined threshold; and

eighth logic configured to determine that the high-side switch is to be enabled in response to a determination that the monitored voltage reaches the predetermined threshold.

12. The power converter of claim 8 , wherein an amount in which the frequency is adjusted is based on a difference between the sampled voltage and the previously-sampled voltage of the node.

13. The power converter of claim 8 , wherein the power converter is a buck converter.

14. The power converter of claim 8 , wherein the voltage sampling logic is configured to sample the voltage at the node and wherein the adjustment logic is configured to generate the second control signal during a discontinuous current mode of the power converter.

15. A power converter, comprising:

a high-side transistor comprising a first gate terminal, a first source terminal, and a first drain terminal;

a low-side transistor comprising a second gate terminal, a second source terminal, and a second drain terminal;

a node coupled to the first drain terminal and the second drain terminal;

voltage sampling logic coupled to the node, the voltage sampling logic configured to sample a voltage at the node; and

adjustment logic configured to generate a first control signal that causes a frequency at which a second control signal is provided to the first gate terminal to be adjusted based at least on the sampled voltage, the second control signal causing the high-side transistor to be enabled when the second control signal reaches a threshold voltage, wherein the adjustment logic comprises:

first logic configured to determine whether the sampled voltage is greater than a previously-sampled voltage of the node;

second logic configured to set the first control signal in a manner that causes the frequency at which the second control signal is provided to be adjusted in the same direction as was performed during a previous cycle in response to a determination that the sampled voltage is greater than the previously-sampled voltage of the node; and

third logic configured to set the first control signal in a manner that causes the frequency at which the second control signal is provided to be adjusted in an opposite direction than was performed during the previous cycle in response to a determination that the sampled voltage is not greater than the previously-sampled voltage of the node.

16. The power converter of claim 15 , wherein the voltage sampling logic comprises:

fourth logic configured to determine that the high-side transistor is to be enabled; and

fifth logic configured to sample the voltage in response to a determination that the high-side switch is to be enabled.

17. The power converter of claim 16 , wherein the fourth logic comprises:

sixth logic configured to monitor a voltage of the second control signal;

seventh logic configured to determine that the monitored voltage reaches a predetermined threshold; and

eighth logic configured to determine that the high-side transistor is to be enabled in response to a determination that the monitored voltage reaches the predetermined threshold.

18. The power converter of claim 17 , wherein the predetermined threshold is the threshold voltage.

19. The power converter of claim 15 , wherein the power converter is a buck converter.

20. The power converter of claim 15 , wherein the voltage sampling logic is configured to sample the voltage at the node and wherein the adjustment logic is configured to generate the first control signal during a discontinuous current mode of the power converter.

21. A power converter, comprising:

a high-side switch;

a low-side switch;

a node coupled to the high-side switch and the low-side switch;

voltage sampling logic coupled to the node, the voltage sampling logic configured to sample a voltage at the node, wherein the voltage sampling logic comprises:

first logic configured to determine that the high-side switch is to be enabled; and

second logic configured to sample the voltage in response to a determination that the high-side switch is to be enabled, wherein the first logic comprises:

third logic configured to monitor a voltage of a third control signal configured to enable the high-side switch;

fourth logic configured to determine that the monitored voltage reaches a predetermined threshold; and

fifth logic configured to determine that the high-side switch is to be enabled in response to a determination that the monitored voltage reaches the predetermined threshold; and

adjustment logic configured to generate a first control signal that adjusts a frequency of an oscillating signal based at least on the sampled voltage, the frequency-adjusted oscillating signal being used to generate a second control signal that causes the high-side switch to be enabled.

22. A power converter, comprising:

a high-side transistor comprising a first gate terminal, a first source terminal, and a first drain terminal;

a low-side transistor comprising a second gate terminal, a second source terminal, and a second drain terminal;

a node coupled to the first drain terminal and the second drain terminal;

voltage sampling logic coupled to the node, the voltage sampling logic configured to sample a voltage at the node, wherein the voltage sampling logic comprises:

first logic configured to determine that the high-side transistor is to be enabled; and

second logic configured to sample the voltage in response to a determination that the high-side switch is to be enabled, wherein the first logic comprises:

third logic configured to monitor a voltage of the second control signal;

fourth logic configured to determine that the monitored voltage reaches a predetermined threshold; and

fifth logic configured to determine that the high-side transistor is to be enabled in response to a determination that the monitored voltage reaches the predetermined threshold; and

adjustment logic configured to generate a first control signal that causes a frequency at which a second control signal is provided to the first gate terminal to be adjusted based at least on the sampled voltage, the second control signal causing the high-side transistor to be enabled when the second control signal reaches a threshold voltage.

Assignments (6)