Voltage regulator bypass resistance control
Embodiments for at least one method and apparatus of controlling a bypass resistance of a voltage regulator are disclosed. One method includes generating a regulated output voltage based upon a switching voltage. The switching voltage is generated through controlled closing and opening of a series switch element and a shunt switch element, the series switch element and the shunt switch element being connected between voltages based on an input voltage. Control of a duty cycle of the switching voltage is provided by sensing and feeding back the regulated output voltage. The bypass resistance is controlled based on an integration of a difference between the duty cycle and a maximum duty cycle.
1. A method of controlling a bypass resistance of a voltage regulator, comprising:
generating a regulated output voltage based upon a switching voltage;
generating the switching voltage through controlled closing and opening of a series switch element and a shunt switch element, the series switch element and the shunt switch element being connected between voltages based on an input voltage;
controlling a duty cycle of the switching voltage by sensing and feeding back the regulated output voltage;
controlling the bypass resistance based on an integration of a difference between the duty cycle and a maximum duty cycle.
2. The method of claim 1 , wherein the bypass resistance couples the input voltage to the regulated output voltage.
3. The method of claim 1 , wherein the bypass resistance is controllably turned on if a parameter related to the duty cycle is sensed to be above a first threshold.
4. The method of claim 1 , wherein the bypass resistance is controllably turned off if a parameter related to the duty cycle is sensed to be below a second threshold.
5. The method of claim 1 , wherein the control of the bypass resistance comprises frequency detection of the switching voltage.
6. The method of claim 1 , wherein a frequency of the switching voltage is substantially maintained while controllably adjusting the bypass resistance.
7. A method of controlling a bypass element of a voltage regulator, comprising:
generating a regulated output voltage based upon a switching voltage;
generating a switching voltage through controlled closing and opening of a series switch element and a shunt switch element, the series switch element and the shunt switch element being connected between voltages based on an input voltage;
simultaneously controlling a duty cycle of the switching voltage, and a conductance of the bypass element,
wherein the simultaneous control comprises a pulse-width modulation loop and a bypass control loop, wherein the pulse-width modulation loop determines the duty cycle based on the output voltage, and the bypass control loop determines the conductance of the bypass element based on an integration of a difference between the duty cycle and a maximum duty cycle.
8. The method of claim 7 , wherein the bypass element couples the input voltage to the regulated output voltage.
9. The method of claim 7 , wherein the bypass element is controllably turned on if a parameter related to the duty cycle is sensed to be above a first threshold.
10. The method of claim 7 , wherein the bypass element is controllably turned off if a parameter related to the duty cycle is sensed to be below a second threshold.
11. The method of claim 7 , wherein the control of the bypass element comprises frequency detection of the switching voltage.
12. The method of claim 7 , wherein a frequency of the switching voltage is substantially maintained while controllably adjusting the bypass element.
13. A method of controlling a bypass resistance of a voltage regulator, comprising:
generating a regulated output voltage based upon a switching voltage;
generating the switching voltage through controlled closing and opening of a series switch element and a shunt switch element, the series switch element and the shunt switch element being connected between voltages based on an input voltage;
providing a control of a duty cycle of the switching voltage by sensing and feeding back the regulated output voltage with a pulse-width modulation loop;
controlling the bypass resistance based on a parameter related to the duty cycle with a bypass control loop, wherein a response time of the pulse-width modulation loop is faster than a response time of the bypass control loop.
14. The method of claim 13 , wherein the bypass resistance couples the input voltage to the regulated output voltage.
15. The method of claim 13 , wherein the bypass resistance is controllably turned on if a parameter related to the duty cycle is sensed to be above a first threshold.
16. The method of claim 13 , wherein the bypass resistance is controllably turned off if a parameter related to the duty cycle is sensed to be below a second threshold.
17. The method of claim 13 , wherein the control of the bypass resistance comprises frequency detection of the switching voltage.
18. The method of claim 13 , wherein a frequency of the switching voltage is substantially maintained while controllably adjusting the bypass resistance.
19. A voltage regulator, comprising:
a series switch element and a shunt switch element connected between voltages based on an input voltage;
means for generating a switching voltage through controlled closing and opening of the series switch element and the shunt switch element;
means for generating a regulated output voltage based upon a switching voltage;
a duty cycle controller for controlling a duty cycle of the switching voltage by sensing and feeding back the regulated output voltage;
a bypass resistance coupled between the input voltage and the regulated output voltage; and
means for controlling the bypass resistance based on an integration of a difference between the duty cycle and a maximum duty cycle.