Modulated power supply system and method with automatic transition between buck and boost modes

1. A modulated power supply system comprising:

a switching converter configured to provide a switching voltage at an output terminal for supplying modulated power to a load; and

a controller configured to perform steps to:

determine if the modulated power supply system is operating in an average power tracking (APT) mode;

operate the modulated power supply system in a buck mode if the APT mode is determined to be enabled;

monitor a switching output voltage of the modulated power supply system to detect a signal indicative of a first predetermined condition corresponding to a drop below a regulated voltage level of the switching output voltage;

automatically transition from the buck mode to a boost mode if the first predetermined condition exists for a predetermined time;

monitor the switching output voltage of the modulated power supply system to detect a signal indicative of a second predetermined condition corresponding to a rise above the regulated voltage level of the switching output voltage;

automatically transition from the boost mode to the buck mode if the second predetermined condition exists for the predetermined period; and

repeat the steps until the controller determines that the APT mode is no longer enabled.

2. The modulated power supply system of claim 1 wherein a switching output voltage at the output terminal is boosted by the switching converter to 1.5 times a voltage of a battery that supplies the switching converter.

3. The modulated power supply system of claim 1 wherein a switching output voltage at the output terminal is toggled by the switching converter between a voltage of a battery that supplies the switching converter to 1.5 times the voltage of the battery during a voltage boost operation.

4. The modulated power supply system of claim 1 wherein the switching output voltage at the output terminal is toggled by the switching converter between a voltage of a battery that supplies the switching converter to 2 times the voltage of the battery during a voltage boost operation.

5. The modulated power supply system of claim 1 wherein the controller is adapted to automatically transition the switching converter from the boost mode to the buck mode upon detecting a duty cycle of 0% for the switching output voltage at the output terminal.

6. The modulated power supply system of claim 5 wherein the switching output voltage at the output terminal is bucked to a battery voltage of a battery that supplies the switching converter.

7. The modulated power supply system of claim 1 further including an inductor coupled between the output terminal and the load.

8. The modulated power supply system of claim 7 wherein the inductor has an inductance less than 2 μH.

9. The modulated power supply system of claim 7 wherein the inductor has an inductance that ranges from 0.5 μH to 1.5 μH.

10. A method of automatically controlling a modulated power supply system via a controller comprising steps of:

determining if the modulated power supply system is operating in an average power tracking (APT) mode;

operating the modulated power supply system in a buck mode if the APT mode is determined to be enabled;

monitoring a switching output voltage of the modulated power supply system to detect a signal indicative of a first predetermined condition corresponding to a drop below a regulated voltage level of the switching output voltage;

automatically transitioning from the buck mode to a boost mode if the first-predetermined condition exists for a predetermined period;

monitoring the switching output voltage of the modulated power supply system to detect a signal indicative of a second predetermined condition corresponding to a rise above the regulated voltage level of the switching output voltage;

automatically transitioning from the boost mode to the buck mode if the second predetermined condition exists for the predetermined period; and

repeating the steps until it is determined that the APT mode is no longer enabled.

11. The method of automatically controlling the modulated power supply system via the controller of claim 10 wherein the predetermined period ranges from 2 μS to 4 μS.

12. The method of automatically controlling the modulated power supply system via the controller of claim 10 wherein the first predetermined condition is a duty cycle of 100% for the switching output voltage at an output terminal.

13. The method of automatically controlling the modulated power supply system via the controller of claim 12 wherein automatically transitioning from the buck mode to the boost mode if the first predetermined condition exists for the predetermined period results in boosting a battery voltage to a voltage equal to 1.5 times the battery voltage.

14. The method of automatically controlling the modulated power supply system via the controller of claim 12 wherein automatically transitioning from the buck mode to the boost mode if the first predetermined condition exists for the predetermined period results in boosting a battery voltage to a voltage equal to 2 times the battery voltage.

15. The method of automatically controlling the modulated power supply system via the controller of claim 10 wherein the second predetermined condition is a duty cycle of 0% for the switching output voltage at an output terminal.

16. The method of automatically controlling the modulated power supply system via the controller of claim 15 wherein automatically transitioning from the boost mode to the buck mode if the second predetermined condition exists for the predetermined period results in bucking a battery voltage to a voltage equal to the battery voltage.