System and method for starting up a high density isolated DC-to-DC power converter

1. A DC-to-DC power converter comprising:

a transformer comprising a primary side and a secondary side;

a primary circuit electrically coupled to said primary side of said transformer, said primary circuit comprising:

at least one first gate driver;

a bias voltage generator; and

a primary microcontroller electrically coupled to said bias voltage generator and configured to receive a first bias voltage supplied by said bias voltage generator, said primary microcontroller configured to provide a first energizing signal to said at least one first gate driver in response to the first bias voltage; and

a secondary circuit electrically coupled to said secondary side of said transformer, said secondary circuit comprising:

a rectifier circuit comprising a plurality of switching elements;

at least one second gate driver communicatively coupled to the rectifier circuit and configured to selectively operate said switching elements; and

a secondary microcontroller communicatively coupled to said primary microcontroller, said secondary microcontroller configured to receive a second bias voltage, said secondary microcontroller further configured to provide a second energizing signal to said at least one first gate driver in response to the second bias voltage, said secondary microcontroller further configured to provide an instruction to said primary microcontroller that causes said primary microcontroller to relinquish control of said primary circuit to said secondary microcontroller, and, in response to receiving control of said primary circuit from said primary microcontroller, said secondary microcontroller further configured to provide a third energizing signal to operate said switching elements.

2. The DC-to-DC power converter of claim 1 , wherein the secondary circuit further comprises a step-down converter electrically coupled between at least one of i) said secondary side of said transformer and said secondary microcontroller and ii) an output voltage bus of said DC-to-DC power converter and said secondary microcontroller, said step-down converter arranged to generate the second bias voltage.

3. The DC-to-DC power converter of claim 1 , further comprising a first isolation circuit coupled between said primary microcontroller and said secondary microcontroller, said secondary microcontroller configured to route the second energizing signal to said at least one first gate driver through said first isolation circuit.

4. The DC-to-DC power converter of claim 1 , further comprising a second isolation circuit coupled between said primary microcontroller and said secondary microcontroller, said secondary microcontroller configured to route the instruction to relinquish control of said primary circuit through said second isolation circuit.

5. The DC-to-DC power converter of claim 1 , wherein said rectifier circuit is electrically coupled between said secondary side of said transformer and an output voltage bus.

6. The DC-to-DC power converter of claim 1 , further comprising a bias winding coupled to said bias voltage generator.

7. The DC-to-DC power converter of claim 1 , wherein the first energizing signal is a series of fixed frequency, constant on-time pulses, and wherein the second energizing signal is at least one of i) pulse width modulated (PWM) signals and ii) pulse frequency modulated (PFM) signals.

8. The DC-to-DC power converter of claim 1 , wherein the bias voltage generator is a linear regulator selected from the group consisting of a low-dropout regulator, a fixed regulator, a variable regulator, and a series regulator.

9. A DC-to-DC power converter comprising:

a transformer comprising a primary side and a secondary side;

a primary circuit electrically coupled to said primary side of said transformer, said primary circuit including a primary microcontroller configured to generate a first energizing signal that energizes a portion of said primary circuit; and

a secondary circuit electrically coupled to said secondary side of said transformer, said secondary circuit including:

a rectifier circuit comprising a plurality of switching elements;

at least one gate driver communicatively coupled to the rectifier circuit and configured to selectively operate said switching elements; and

a secondary microcontroller communicatively coupled to said primary microcontroller, said secondary microcontroller configured to provide an instruction to said primary microcontroller that causes said primary microcontroller to relinquish control of said primary circuit to said secondary microcontroller, said secondary microcontroller further configured to provide a second energizing signal to the portion of said primary circuit, and, in response to receiving control of said primary circuit from said primary microcontroller, said secondary microcontroller further configured to provide a third energizing signal to operate said switching elements.

10. The DC-to-DC power converter of claim 9 , wherein said secondary circuit further includes a step-down converter electrically coupled between said secondary side of said transformer and said secondary microcontroller, said step-down converter configured to step an output voltage induced in said secondary side of said transformer down to a bias voltage.

11. The DC-to-DC power converter of claim 9 , further comprising a first isolation circuit coupled between said primary microcontroller and said secondary microcontroller, said secondary microcontroller configured to provide the second energizing signal to the portion of said primary circuit through said first isolation circuit.

12. The DC-to-DC power converter of claim 9 , further comprising a second isolation circuit coupled between said primary microcontroller and said secondary microcontroller, said secondary microcontroller configured to route the instruction to relinquish control of said primary circuit through said second isolation circuit.

13. The DC-to-DC power converter of claim 9 , wherein said rectifier circuit is electrically coupled between said secondary side of said transformer and an output voltage bus.

14. The DC-to-DC power converter of claim 9 , further comprising a bias voltage generator and a bias winding, said bias voltage generator electrically coupled to said primary microcontroller through said bias winding.

15. The DC-to-DC power converter of claim 9 , wherein the first energizing signal is a series of fixed frequency, constant on time pulses, and wherein the second energizing signal is at least one of i) pulse width modulated (PWM) signals and ii) pulse frequency modulated (PFM) signals.

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

receiving, by a primary microcontroller disposed within a primary circuit of the DC-to-DC power converter, a first bias voltage;

generating, by the primary microcontroller and in response to the first bias voltage, a first energizing signal that energizes a portion of the primary circuit;

receiving, by the primary microcontroller and from a secondary microcontroller disposed within a secondary circuit of the DC-to-DC power converter, an instruction to relinquish control of the primary circuit to the secondary microcontroller;

transmitting, by the secondary microcontroller, a second energizing signal to the portion of the primary circuit; and

generating, by the secondary microcontroller and in response to receiving control of said primary circuit, a third energizing signal to operate switching elements of a rectifier circuit disposed within the secondary circuit.

17. The method of claim 16 , further comprising receiving, by the secondary microcontroller, a second bias voltage from a non-isolated step-down converter coupled to a secondary side of a transformer, the transformer coupled between the primary circuit and the secondary circuit.

18. The method of claim 17 , further comprising routing, by the secondary microcontroller, the second energizing signal to the portion of the primary circuit through a first digital isolator coupled between the primary circuit and the secondary circuit.

19. The method of claim 18 , further comprising routing, by the secondary microcontroller, the instruction to relinquish control of the primary circuit through a second digital isolator coupled between the primary circuit and the secondary circuit.

20. The method of claim 17 , further comprising routing, by the secondary microcontroller, the second energizing signal to the portion of the primary circuit through a first optocoupler coupled between the primary circuit and the secondary circuit.

21. The method of claim 20 , further comprising routing, by the secondary microcontroller, the instruction to relinquish control of the primary circuit through a second optocoupler coupled between the primary circuit and the secondary circuit.

22. The DC-to-DC power converter of claim 1 , wherein the primary microcontroller is further configured to determine a temperature associated with said DC-to-DC power converter and to postpone a start-up sequence of the DC-to-DC power converter based on the determined temperature.

23. The DC-to-DC power converter of claim 9 , wherein the primary microcontroller is further configured to determine a temperature associated with said DC-to-DC power converter and to postpone a start-up sequence of the DC-to-DC power converter based on the determined temperature.