Dynamic converter topology

1. A method of operating a power converter, the method comprising:

monitoring at least one condition of the power converter;

based on the at least one monitored condition, using a converter topology selected between at least a full-bridge converter topology and a half-bridge converter topology to achieve an efficient operation at a then current operational load; and

wherein monitoring at least one condition of the power converter further comprises, when running in the half-bridge converter topology, monitoring the switching frequency.

2. The method of claim 1 , further comprising:

comparing each of the monitored at least one condition with a select threshold; and

changing the converter topology when the monitored at least one condition passes the threshold.

3. The method of claim 1 , wherein monitoring the at least one condition further comprises:

monitoring at least one of output current, output power, phase shift, switching frequency, hold up time and temperature.

4. The method of claim 1 , wherein monitoring at least one condition of the power converter further comprises:

when running in the full-bridge converter topology, monitoring the phase shift.

5. The method of claim 1 , further comprising:

selectively disabling the power converter's ability to switch between the at least full-bridge converter and the half-bridge converter topologies.

6. A method of operating a DC-to-DC power converter, the method comprising:

determining the efficiency of the power converter; and

when it is determined that the power converter is running below a selected efficiency, switching a converter topology of the power converter between a full-bridge converter topology and a half-bridge converter topology, wherein switching from a full-bridge converter topology to a half-bridge converter topology further comprises, from a first and second pair of switching elements, manipulating a first switching element in the second pair to remain open and a second switching element in the second pair to remain closed.

7. The method of claim 6 , wherein switching from a half-bridge converter topology to a full-bridge converter topology further comprises:

allowing the first switching element in the second pair of switching elements and the second switching element in the second pair of switching elements to open and close in a usual manner for full-bridge converter operation.

8. The method of claim 6 , wherein determining the efficiency of the power converter further comprises:

monitoring at least one condition related to efficiency; and

comparing each of the at least one variables to a defined threshold.

9. The method of claim 8 , wherein monitoring the at least one condition further comprises:

monitoring at least one of output current, output power, phase shift, switching frequency, hold up time and temperature.

10. The method of claim 8 , wherein monitoring at least one condition further comprises:

when running in the full-bridge converter topology, monitoring the phase shift.

11. The method of claim 8 , wherein monitoring at least one condition further comprises:

when running in the half-bridge converter topology, monitoring the switching frequency.

12. A voltage converter circuit, the circuit comprising:

at least first and second voltage converter topologies, wherein the first voltage converter topology is a full-bridge converter topology and the second voltage converter topology is a half-bridge converter topology;

an output node;

a controller operable to implement one of the first and second voltage converter topologies to provide an output power to the output node in response to a parameter associated with an output load; and

wherein the controller is further operable to switch from a full-bridge converter topology to a half-bridge converter topology by manipulating a first switching element in the second pair to remain open and a second switching element in the second pair to remain closed, and switch from a half-bridge converter topology to a full-bridge converter topology by allowing the first switching element in the second pair and the second switching element in the second pair to open and close in a usual manner for full-bridge converter operation.

13. The voltage converter of claim 12 , wherein the at least first and second voltage converter topologies share a first and second pair of switching elements.

14. The voltage converter of claim 12 , wherein the controller is further operable to manipulate the second pair of switching elements to change between the first and second voltage converter topologies.

15. A DC-to-DC voltage converter, the converter comprising:

a first rail having a first end configured to receive a signal at a first potential;

a second rail having a first end configured to receive a signal at a second potential;

an input inductor coupled to the first rail;

a first switching mechanism coupled between the first and second rail configured to control a regulated output of the converter;

a first and second pair of switching mechanisms that form a converter topology of the converter, the first and the second pair of switching elements coupled across the first and the second rail;

a transformer having a primary winding selectively coupled across the first and second rails via the first and second pair of switching mechanisms, the transformer further having at least one secondary winding coupled to a low pass filter coupled to and output node;

a controller configured to selectively control the second pair of switching mechanisms to change the converter topology between a full-bridge converter and a half-bridge converter; and

wherein the controller is further configured to switch to a half-bridge converter by maintaining a first switch of the second pair of switching mechanisms open and maintaining a second switch in the second pair of switching mechanism closed.

16. The converter of claim 15 , further comprising:

a bridge rectifier coupled to receive the first and second potential signals, the bridge rectifier further coupled between the first and second rails; and

a power factor correction controller coupled to inductor configured to control the duty cycle of the first switching mechanism.

17. An electronic system, the system comprising:

a varying load device having at least one power input;

a converter having at least one output coupled to the at least one power input of the varying load device; the converter including,

at least first and second voltage converter topologies, wherein the first voltage converter topology is a full-bridge converter topology and the second voltage converter topology is a half-bridge converter topology,

an output node, and

a controller operable to implement one of the first and second voltage converter topologies and operable responsive to a switching frequency of at least one of the first and second voltage converter topologies to implement the other one of the first and second voltage converter topologies;

wherein the converter includes an H-bridge structure including first and second pairs of switching elements, each pair of switching elements including first and second switching elements, and

wherein the controller is further operable to control all the switching elements in the H-bridge structure to operate in the full-bridge converter topology and to open the first switching element and close the second switching element in the second pair and to control the switching elements in the first pair to operate in the half-bridge converter topology when the switching frequency reaches a threshold value.

18. A voltage converter, the circuit comprising:

a plurality of voltage converter circuits, each voltage converter circuit having an associated topology; and

a control circuit coupled to the voltage converter circuits, the control circuit operable to select one of the voltage converter circuits to provide an output power on an output node, and the control circuit operable in response to a switching frequency of the selected voltage converter circuit to select another one of the voltage converter circuits;

wherein the voltage converter includes an H-bridge structure including first and second pairs of switching elements, each pair of switching elements including first and second switching elements, and

wherein the control circuit is operable to control all the switching elements in the H-bridge structure to operate in a full-bridge topology and to open the first switching element and close the second switching element in the second pair and to control the switching elements in the first pair to operate in a half-bridge topology responsive to the switching frequency reaching a threshold value.

19. A voltage converter, the circuit comprising:

a full-bridge voltage converter circuit and an LLC resonant half-bridge voltage converter circuit; and

a control circuit coupled to the full-bridge and LLC resonant half-bridge voltage converter circuits, the control circuit operable in first and second modes to control the full-bridge voltage converter circuit and LLC resonant half-bridge voltage converter circuit, respectively, to provide output power on an output node, the control circuit operable in the first mode to detect a first parameter of the full-bridge voltage converter circuit and switch to the LLC resonant half-bridge voltage converter circuit responsive to the first parameter reaching a first threshold value and operable in the second mode to detect a switching frequency of the LLC resonant half-bridge voltage converter circuit and switch to the full-bridge voltage converter circuit responsive to the switching frequency reaching a second threshold value.

20. The voltage converter of claim 19 , wherein the control circuit is operable responsive to the switching frequency reaching a minimum frequency value to switch to operation of the full-bridge voltage converter circuit.

21. The voltage converter of claim 19 , wherein the LLC resonant half-bridge voltage converter circuit comprises a series LLC resonant half-bridge voltage converter circuit.

22. The voltage converter circuit of claim 19 , wherein the voltage converter includes additional voltage converter circuits, each voltage converter circuit having an associated topology, and wherein the control circuit is operable to detect additional parameters and to switch among the voltage converter circuits responsive to the detected first, second, and additional parameters.

23. The voltage converter of claim 19 ,

wherein the full-bridge voltage converter circuit includes an H-bridge including first, second, third, and fourth switching elements; and

wherein the first parameter comprises a phase shift between control signals being applied to the first and fourth and the second and third switching elements of the H-bridge.

24. The voltage converter of claim 20 , wherein the control circuit generates control signals to control the first, second, third, and fourth switching elements during operation of the full-bridge voltage converter circuit and generates controls signals to open the third switching element and close the fourth switching element to thereby form the LLC resonant half-bridge voltage converter circuit and during operation of the LLC resonant half-bridge voltage converter circuit further generates control signals to control to the first and second switching elements.