US 12,184,179 B2 · Multi-level DC-DC converter

Abstract

Multi-level DC-to-DC converter circuits and methods that permit a full range of output voltages, including near and at zone boundaries. Embodiments alternate among adjacent or near-by zones, operating in a first zone for a selected time and then in a second zone for a selected time. Embodiments may include a parallel capacitor voltage balancing circuit that connects a capacitor to a source voltage to charge that capacitor, or couples two or more capacitors together to transfer charge, all under the control of real-time capacitor voltage measurements. Embodiments may include a lossless voltage balancing solution where out-of-order state transitions are allowed, thus increasing or decreasing the voltage across specific capacitors to prevent voltage overstress on the converter main switches. Restrictions may be placed on the overall sequence of state transitions to reduce or avoid transition state toggling, allowing each capacitor an opportunity to have its voltage steered as necessary for balancing.

Claims20

Dependent claims

A converter circuit for converting an input voltage to an output voltage, including:

(a) a multi-level converter circuit including:
(1) an inner pair of switches coupled in series;
(2) at least one inductor coupled to a node between the inner pair of switches;
(3) at least one outer pair of switches each coupled in series with the inner pair of switches wherein each outer pair of switches brackets the inner pair of switches;
and
(4) at least one capacitor each coupled between a corresponding outer pair of switches and in parallel with the inner pair of switches;
(b) a switched resistance network including a plurality of series-coupled switch and resistance element pairs, all but one switch and resistance element pair being coupled in parallel with a corresponding switch of the outer pair of switches, with the remaining switch and resistance element pair being coupled in parallel with the inner pair of switches;
and
(c) a directional correction circuit, coupled to the at least one capacitor and to the switched resistance network, configured to sense deviations in a voltage across at least one coupled capacitor and generate directional correction signals to the switched resistance network that, alone or in combination, dynamically change a pattern of charge or discharge states for the at least one coupled capacitor to selectively steer the voltage across the at least one coupled capacitor towards a balanced voltage state.

6 more elements

A multi-level DC-to-DC converter circuit for converting an input voltage to a different output voltage, including:

(a) a plurality of main switches coupled in series;
(b) an inductor coupled to a node within the plurality of main switches;
(c) at least one capacitor coupled to at least some of the plurality of main switches and selectively couplable through the plurality of main switches to the inductor and/or a voltage source and/or a voltage sink;
(d) a control circuit coupled to the main switches and configured to set states for the main switches;
(e) a switched resistance network including a plurality of series-coupled switch and resistance element pairs, each series-coupled switch and resistance element pair coupled to at least one capacitor and to at least one main switch;
and
(f) a directional correction circuit, coupled to at least one capacitor and to the switched resistance network, and configured to sense deviations in a voltage across at least one coupled capacitor and generate corresponding directional correction signals to the switched resistance network that, alone or in combination, dynamically change a pattern of charge or discharge states for the at least one coupled capacitor to selectively steer the voltage across the at least one coupled capacitor towards a balanced voltage state.

4 more elements

A method for balancing capacitor voltages in a converter circuit for converting an input voltage to an output voltage, the converter circuit including (1) a multi-level converter circuit including at least four switches, at least one capacitor, and at least one inductor, (2) a control circuit coupled to the multi-level converter circuit and configured to set states for the switches, and (3) a switched resistance network, coupled to at least one capacitor and to at least one switch of the at least four switches, the method including:

(a) sensing deviations in a voltage across the at least one capacitor;
(b) generating directional correction signals corresponding to the sensed deviations;
and
(c) applying the generated directional correction signals, alone or in combination, to the switched resistance network to selectively steer the voltage across the at least one capacitor towards a balanced voltage state by dynamically changing the charge on the at last one coupled capacitor in response to the generated direction correction signals.

1 more element

Dependencies are inferred from the claim text.

Multi-level DC-DC converter

Life of this patent

Multi-level DC-DC converter

Life of this patent

Abstract

Claims20