US 2011/0299301 A1 · FIXED-FREQUENCY LLC RESONANT POWER REGULATOR

Abstract

An LLC resonant AC/DC power regulator system (10) includes a transformer (20) comprising a primary inductor and a secondary inductor. An LLC resonant tank (18) is configured to have first and second resonant frequencies. A full-bridge is coupled between first and second voltages and includes a first pair of switches coupled between the first and second voltages and a second pair of switches coupled between the first and second voltages. The LLC resonant tank (18) is coupled between a first node that interconnects the first pair of switches and a second node that interconnects the second pair of switches. The switches (16) are activated and deactivated to generate a resonant current through the LLC resonant tank (18) in response respective switching control signals. The respective switching control signals have fixed frequency and regulated duty-cycle to activate the plurality of switches in a zero voltage switching (ZVS) manner. An output stage (22) is coupled to the secondary inductor and comprising at least one output rectifier (24) that is configured to conduct an output current that is generated in the secondary inductor in response to the resonant current. The out stage (22) generates a rectified output voltage at an output based on the output current.

Claims20

Dependent claims

An LLC resonant AC/DC power regulator system comprising:

a transformer comprising a primary inductor and a secondary inductor;
an LLC resonant tank comprising a resonant capacitor and a leakage inductor coupled in series with the primary inductor, the LLC resonant tank being configured to have a first resonant frequency and a second resonant frequency;
an input stage comprising a full-bridge coupled between an input voltage and a reference voltage, the full-bridge comprising a first pair of switches coupled between the input voltage and the reference voltage and a second pair of switches coupled between the input voltage and the reference voltage, the LLC resonant tank interconnected between a first node that interconnects the first pair of switches and a second node that interconnects the second pair of switches, the switches being activated and deactivated to generate a resonant current through the LLC resonant tank in response respective switching control signals, the respective switching control signals having fixed frequency and regulated duty-cycle control to operate the switches of the full-bridge in a zero voltage switching (ZVS) manner;
and
an output stage coupled to the secondary inductor and comprising at least one output rectifier that is configured to conduct an output current that is generated in the secondary inductor in response to the resonant current, the output stage generating a rectified output voltage at an output based on the output current.

2 more elements

An LLC resonant power regulator system comprising:

a switching control stage configured to generate a plurality of switching control signals having a substantially fixed frequency and regulated duty-cycle;
an LLC resonant tank comprising a primary inductor of a transformer, a leakage inductor, and a resonant capacitor arranged in series;
an input stage comprising a plurality of switches arranged as a full-bridge and being controlled by the respective plurality of switching control signals to activate and deactivate in a predetermined sequence to provide an alternating voltage potential across output nodes thereof, the LLC resonant tank being coupled the output nodes of the input stage, the LLC resonant tank generating a resonant current through the LLC resonant tank according to the activation and deactivation of the plurality of switches;
and
an output stage comprising at least one rectifier configured to alternately conduct an output current that is generated by a secondary inductor of the transformer in response to the resonant current to provide a rectified output voltage at an output thereof.

2 more elements

A method for generating an output voltage via an LLC resonant power regulator, the method comprising:

generating a plurality of switching control signals having a substantially fixed frequency and regulated duty-cycle;
controlling switches of a full-bridge circuit in a predetermined sequence in response to the plurality of switching control signals to provide an alternating voltage potential across output nodes of the full-bridge circuit, the full-bridge circuit being connected between an input voltage and a reference voltage;
generating a resonant current through an LLC resonant tank in response to the alternating voltage potential, the LLC resonant tank comprising a series connection of a primary inductor of a transformer, a leakage inductor, and a resonant capacitor coupled between the output nodes of the full-bridge circuit;
discharging a parasitic capacitor associated with each of the switches in the predetermined sequence in response to the resonant current to facilitate operating the switches in a zero voltage switching (ZVS) manner;
generating an output current at a secondary inductor of the transformer;
and
conducting the output current through at least one rectifier in a zero current switching (ZCS) manner to provide a corresponding output voltage at an output of the LLC resonant power regulator.

4 more elements

Dependencies are inferred from the claim text.

Fixed-frequency llc resonant power regulator

Life of this patent

Fixed-frequency llc resonant power regulator

Life of this patent

Abstract

Claims20