US 10,483,855 B2 · Power limit protection for resonant power converter

Abstract

A circuit comprises an Inductor-Inductor-Capacitor (LLC) tank circuit and an energizing circuit. The LLC tank circuit includes first and second inductors, a capacitor, and a primary coil of a transformer. The first inductor is coupled in series with the second inductor, the second inductor is coupled in series with the capacitor, and the primary coil is coupled in parallel with the second inductor. The energizing circuit supplies power to the LLC tank circuit according to a switching period, and detects a power limit condition according to a value of an integrated current sense signal and a duration of the switching period. The integrated current sense signal corresponds to an integration over time of a current supplied to the LLC tank circuit. The circuit may be incorporated into a power converter to provide power limit detection according to an accurate real-time estimation of the power converter's output power.

Claims19

Dependent claims

An electronic circuit comprising:

an Inductor-Inductor-Capacitor (LLC) tank circuit comprising a first inductor, a second inductor, a capacitor, and a primary coil of a transformer, wherein the first inductor is coupled in series with the second inductor, the second inductor is coupled in series with the capacitor, and the primary coil of the transformer is coupled in parallel with the second inductor;
and
an energizing circuit to supply power to the LLC tank circuit according to a switching period and to detect a power limit condition, wherein the power limit condition is detected according to a value of an integrated current sense signal and a duration of the switching period, wherein the integrated current sense signal corresponds to an integration over time of a current supplied to the LLC tank circuit by a first switch, and wherein the energizing circuit comprises:
an oscillator to receive a feedback signal and to generate a clock signal having the switching period according to the feedback signal;
the first switch to supply power to the LLC tank circuit from an input voltage during a first phase of the clock signal;
a second switch to configure components of the LLC tank circuit in a loop circuit during a second phase of the clock signal;
a ramp signal generation circuit to generate a constant dv/dt threshold signal according to the switching period;
and
a comparator circuit to detect the power limit condition according to a comparison of the constant dv/dt threshold signal and the integrated current sense signal.

6 more elements

An electronic circuit comprising:

an Inductor-Inductor-Capacitor (LLC) tank circuit comprising a first inductor, a second inductor, a capacitor, and a primary coil of a transformer, wherein the first inductor is coupled in series with the second inductor, the second inductor is coupled in series with the capacitor, and the primary coil of the transformer is coupled in parallel with the second inductor;
and
an energizing circuit to supply power to the LLC tank circuit according to a switching period and to detect a power limit condition, wherein the power limit condition is detected according to a value of an integrated current sense signal and a duration of the switching period, wherein the integrated current sense signal corresponds to an integration over time of a current supplied to the LLC tank circuit by a first switch, and wherein the energizing circuit comprises:
an oscillator to receive a feedback signal and to generate a clock signal having the switching period according to the feedback signal;
the first switch to supply power to the LLC tank circuit from an input voltage during a first phase of the clock signal;
a second switch to configure components of the LLC tank circuit in a loop circuit during a second phase of the clock signal;
a counter circuit to generate a count according to the switching period;
a divider circuit to produce a power estimation signal by dividing the integrated current sense signal by the count;
and
a comparator circuit to detect the power limit condition according to a comparison of the power estimation signal to a power limit threshold having a predetermined value.

7 more elements

An electronic circuit comprising:

an Inductor-Inductor-Capacitor (LLC) tank circuit comprising a first inductor, a second inductor, a capacitor, and a primary coil of a transformer, wherein the first inductor is coupled in series with the second inductor, the second inductor is coupled in series with the capacitor, and the primary coil of the transformer is coupled in parallel with the second inductor;
and
an energizing circuit to supply power to the LLC tank circuit according to a switching period and to detect a power limit condition, wherein the power limit condition is detected according to a value of an integrated current sense signal and a duration of the switching period, wherein the integrated current sense signal corresponds to an integration over time of a current supplied to the LLC tank circuit by a first switch, and wherein the energizing circuit comprises:
an oscillator to receive a feedback signal and to generate a clock signal having the switching period according to the feedback signal;
the first switch to supply power to the LLC tank circuit from an input voltage during a first phase of the clock signal;
a second switch to configure components of the LLC tank circuit in a loop circuit during a second phase of the clock signal;
a polynomial calculation circuit to generate a power estimation signal by evaluating a polynomial using a value of the integrated current sense signal;
and
a comparator circuit to detect the power limit condition according to a comparison of the power estimation signal to a power limit threshold having a predetermined value.

6 more elements

Dependencies are inferred from the claim text.

Power limit protection for resonant power converter

Life of this patent

Power limit protection for resonant power converter

Life of this patent

Abstract

Claims19