Resonant switching power converter with adaptive dead time control
AssigneeCirrus Logic, Inc.
InventorsJohn L. Melanson, Mauro L. Gaetano
Life of this patent
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Abstract
A resonant switching power converter having adaptive dead time control provides improved efficiency along with reduced EMI/audible noise and component stresses. A dead time between pulses generated by a switching circuit is adaptively set in conformity with a value of the input voltage to the resonant switching power converter and an indication of a magnitude of the current passing through inductive element of the resonant tank of the converter. The indication of the current magnitude may be the switching frequency of the converter, or a measure of line or load current levels. The dead time can be obtained from a look-up table or computed from the current magnitude and input voltage values.
Claims20
A resonant switching power circuit, comprising:
- a resonant circuit including at least one inductance and at least one capacitance for transferring energy to an output of the resonant switching power circuit;
- a switching circuit coupled to the resonant circuit for transferring energy from an input voltage source to the resonant circuit, wherein the switching circuit includes a first transistor for selectively coupling the resonant circuit to an output node of the input voltage source and a second transistor for selectively coupling the resonant circuit to a return node of the input voltage source;
- and
- a control circuit for controlling the switching circuit such that a dead time between de-activation of one of the first transistor or the second transistor and activation of a second one of the first transistor or the second transistor is dynamically set in dependence on an indication of a magnitude of a current flowing through the inductance and a value of a voltage of the input voltage source.
A method of controlling switching in a resonant switching power circuit, the method comprising:
- transferring energy to an output of the resonant switching power circuit from a resonant tank circuit;
- transferring energy from an input voltage source to the resonant circuit by operating a switching circuit;
- and
- controlling a dead-time between pulses of the switching circuit in conformity with a voltage of the input voltage source and an indication of a magnitude of a current flowing through an inductance of the resonant tank circuit.
An integrated circuit controller, integrated on a single die, for controlling a resonant switching power converter, wherein the integrated circuit controller provides control signals to a switching circuit that generates pulses provided to an input of a resonant tank circuit that transfers power to a load from an input voltage source, and wherein the controller includes a control circuit for controlling a dead-time between the pulses in conformity with a voltage of the input voltage source and an indication of a magnitude of a current flowing through an inductance of the resonant tank circuit.
Dependencies are inferred from the claim text.