Self-oscillating resonant power converter

Patent metadata

Field	Value
Publication number	US-9735676-B2
Application number	US-201314439412-A
Country	US
Kind code	B2
Filing date	Oct 29, 2013
Priority date	Nov 2, 2012
Publication date	Aug 15, 2017
Grant date	Aug 15, 2017

Abstract

Resonant power converters and inverters comprising a self-oscillating feedback loop coupled from a switch output to a control input of a switching network comprising one or more semiconductor switches (S 1 , S 2 ). The self-oscillating feedback loop sets a switching frequency of the power converter ( 100 ) and comprises a first intrinsic switch capacitance (CGD) coupled between a switch output and a control input of the switching network and a first inductor (LG). The first inductor (LG) is coupled in-between a first bias voltage source and the control input of the switching network and has a substantially fixed inductance. The first bias voltage source is configured to generate an adjustable bias voltage (VBias) applied to the first inductor (LG). The output voltage (V 0 UT) of the power converter ( 100 ) is controlled in a flexible and rapid manner by controlling the adjustable bias voltage (VBias).

First claim

The invention claimed is:

1. A resonant power converter comprising:
an input terminal for receipt of an input voltage;
a switching network comprising a first semiconductor switch controlled by a control input;
the switching network comprising a switch input operatively coupled to the input terminal for receipt of the input voltage and a switch output operatively coupled to an input of a resonant network of the resonant power converter;
the resonant network comprising a predetermined resonance frequency (fR) and an output operatively coupled to a converter output terminal; and
a self-oscillating, feedback loop coupled from the switch output to a control input of the switching network to set a switching frequency of the power converter, the self-oscillating feedback loop further comprising:
a first intrinsic switch capacitance coupled between the switch output and the control input of the switching network;
a first bias voltage source configured to generate a first adjustable bias voltage;
a first inductor with substantially fixed inductance coupled in-between the first bias voltage source and the control input of the switching network; and
a voltage regulation loop configured to control an output voltage of the power converter by controlling the first adjustable bias voltage applied to the first inductor,
wherein the substantially fixed inductance of the first inductor is set such that a peak voltage at the control input of the switching network exceeds a threshold voltage of the first semiconductor switch of the switching network.

2. The resonant power converter according to claim 1 , further comprising:
an input inductor coupled between the input terminal and the switch input and wherein the control terminal of the first semiconductor switch is coupled to the control input of the switching network and an output terminal of the first semiconductor switch is coupled to the switch input and to the switch output.

3. The resonant power converter according to claim 2 , wherein the input inductor and the first inductor are magnetically coupled with a predetermined magnetic coupling coefficient.

4. The resonant power converter according to claim 1 , wherein the
first semiconductor switch is coupled between the switch output and a voltage supply rail of the resonant power converter and the control terminal of the first semiconductor switch is coupled to the control input of the switching network,
a second semiconductor switch coupled between the switch output and the input terminal; and
wherein a control terminal of the second semiconductor switch is coupled to a second bias voltage source through a cascade of a second inductor with substantially fixed inductance and a third inductor with substantially fixed inductance, and
wherein a feedback capacitor is coupled between the switch output and an intermediate node between the second and third inductors.

5. The resonant power converter according to claim 4 , wherein the first inductor and the third inductor are magnetically coupled with a predetermined magnetic coupling coefficient.

6. The resonant power converter according to claim 1 , wherein the voltage regulation loop comprises:
a reference voltage generator supplying a reference DC or AC voltage to a first input of a comparator,
a second input of the comparator being coupled to the converter output voltage, an output of the of the comparator operatively coupled to a control input of the first bias voltage source.

7. The resonant power converter according to claim 1 , wherein the first inductor has an inductance between 1 nH and 10 μH.

8. A resonant power converter according to claim 1 , wherein the substantially fixed inductance of the first inductor is selected such that a peak-peak voltage swing at the control input of the switching network is approximately equal to a numerical value of the threshold voltage of the at least one of the semiconductor switches of the switching network.

9. The resonant power converter according to claim 1 , wherein the self-oscillating feedback loop further comprises:
a first series resonant circuit coupled in-between the control input of the first semiconductor switch and fixed electric potential of the converter, and
a second series resonant circuit coupled in-between the control input of the first semiconductor switch and the switch output.

10. The resonant power converter according to claim 1 , wherein the self-oscillating feedback loop further comprises:
a parallel resonant circuit coupled in series with the first inductor in-between the first adjustable bias voltage and the first inductor.

11. The resonant power converter according to claim 1 , further comprising:
a rectifier coupled between the output of the resonant network and the converter output terminal to provide a rectified DC output voltage.

12. The resonant power converter according to claim 11 , wherein the rectifier comprises a synchronous rectifier.

13. The resonant power converter according to claim 12 , wherein the synchronous rectifier comprises:
a rectification semiconductor switch configured to rectify an output voltage of the resonant network in accordance with a rectifier control input of the rectification semiconductor switch,
a first rectification inductor with a substantially fixed inductance coupled in-between a fixed or adjustable rectifier bias voltage and the rectifier control input.

14. A resonant power converter according to claim 13 , wherein the fixed or adjustable rectifier bias voltage is coupled to a fixed DC bias voltage source or to the rectified DC output voltage through a resistive or capacitive voltage divider.

15. A resonant power converter assembly comprising:
a resonant power converter according claim 1 ,
a carrier substrate having at least the switching network and the resonant circuit integrated thereon,
an electrical trace pattern of the carrier substrate forming the first inductor.

16. The resonant power converter assembly according to claim 12 , wherein the carrier substrate comprises a semiconductor die.

17. The resonant power converter according to claim 1 , wherein the first inductor has an inductance between 1 nH and 50 nH.

18. A resonant power converter comprising:
an input terminal for receipt of an input voltage;
a switching network comprising a first semiconductor switch controlled by a control input;
the switching network comprising a switch input operatively coupled to the input terminal for receipt of the input voltage and a switch output operatively coupled to an input of a resonant network of the resonant power converter;
the resonant network comprising a predetermined resonance frequency (fR) and an output operatively coupled to a converter output terminal;
a self-oscillating feedback loop coupled from the switch output to a control input of the switching network to set a switching frequency of the power converter, the self-oscillating feedback loop further comprising:
a first intrinsic switch capacitance coupled between the switch output and the control input of the switching network;
a first bias voltage source configured to generate a first adjustable bias voltage;
a first inductor with substantially fixed inductance coupled in-between the first bias voltage source and the control input of the switching network; and
a voltage regulation loop configured to control an output voltage of the power

converter by controlling the first adjustable bias voltage applied to the first inductor, wherein the first semiconductor switch is coupled between the switch output and

Assignees

• Univ Danmarks Tekniske

Inventors

• Madsen Mickey P
• Pedersen Jeppe Arnsdorf

Classifications

• H02M3/1563 Primary

  without using an external clock (H02M3/158 takes precedence) · CPC title

• H02M3/3385 Primary

  with automatic control of output voltage or current (H02M3/33561 takes precedence) · CPC title

• H02M3/1588 Primary

  comprising at least one synchronous rectifier element (H02M3/1582, H02M3/1584 take precedence) · CPC title

• H02M7/5383

  in a self-oscillating arrangement (H02M7/538 takes precedence) · CPC title

• H02M3/158 Primary

  including plural semiconductor devices as final control devices for a single load · CPC title