Device and method for controlling a buck-boost converter
AssigneeIntersil Americas Inc.
InventorsZaki Moussaoui, Jun Liu
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Abstract
A circuit, device, and method for controlling a buck-boost circuit includes a bootstrap capacitor voltage regulator circuit and a comparator circuit. The bootstrap capacitor voltage regulator circuit is electrically coupled to a buck-mode bootstrap capacitor of the buck-boost converter and to a boost-mode bootstrap capacitor of the buck-boost converter. The comparator circuit is configured to control the bootstrap capacitor voltage regulator circuit to maintain a voltage of the bootstrap capacitors above a reference threshold voltage by transferring an amount energy from one of the bootstrap capacitors to the other bootstrap capacitors based on the particular mode of operation of the buck-boost converter.
Claims20
A control circuit to control operation of a buck-boost circuit, the control circuit comprising:
- a bootstrap capacitor voltage regulator circuit electrically coupled to a buck-mode bootstrap capacitor of the buck-boost circuit and to a boost-mode bootstrap capacitor of the buck-boost circuit;
- and
- a comparator circuit electrically coupled to the buck-mode bootstrap capacitor and the boost-mode bootstrap capacitor, the comparator circuit configured (i) to control the bootstrap capacitor voltage regulator circuit to maintain a voltage of the buck-mode bootstrap capacitor above a first reference voltage during a boost mode of the buck-boost circuit and (ii) to control the bootstrap capacitor voltage regulator circuit to maintain a voltage of the boost-mode bootstrap capacitor above a second reference voltage during a buck mode of the buck-boost circuit.
A method for controlling the operation of a buck-boost circuit to convert an input voltage to an output voltage, the buck-boost circuit including a buck-mode bootstrap capacitor and a boost-mode bootstrap capacitor, the method comprising:
- sensing a voltage of the buck-mode bootstrap capacitor;
- sensing a voltage of the boost-mode bootstrap capacitor;
- transferring an amount of energy from the boost-mode bootstrap capacitor to the buck-mode bootstrap capacitor in response to (i) the sensed voltage of the buck-mode bootstrap capacitor being less than a first reference voltage and (ii) the buck-boost converter operating in a boost mode, and
- transferring an amount of energy from the buck-mode bootstrap capacitor to the boost-mode bootstrap capacitor in response to (i) the voltage of the boost-mode bootstrap capacitor being less than a second reference voltage and (ii) the buck-boost converter operating in a buck mode.
A converter comprising:
- an H-bridge buck-boost converter circuit comprising (i) a high-side buck-mode switch, low-side buck-mode switch, and a buck-mode bootstrap capacitor electrically coupled to the high-side buck-mode switch and the low-side buck-mode switch and (ii) a high-side boost-mode switch, a low-side boost-mode switch, and a boost-mode bootstrap capacitor electrically coupled to the high-side boost-mode switch and the low-side boost-mode switch;
- and
- a control circuit electrically coupled to the H-bridge buck-boost converter circuit to maintain a voltage of the buck-mode bootstrap capacitor above a first reference voltage during a boost mode of operation of the H-bridge buck-boost converter circuit and maintain a voltage of the boost-mode bootstrap capacitor above a second reference voltage during a buck mode of operation of the H-bridge buck-boost converter circuit.
An electronic device comprising:
- a power supply circuit configured to generate a supply voltage;
- a converter electrically coupled to the power supply to convert the supply voltage to a converted supply voltage having a voltage magnitude different from the supply voltage, the converter comprising (i) a buck-boost converter circuit including a buck-mode bootstrap capacitor and a boost-mode bootstrap capacitor and (ii) a control circuit electrically coupled to the buck-boost converter circuit to maintain a voltage of the buck-mode bootstrap capacitor above a first reference voltage during a boost mode of the buck-boost converter circuit and maintain a voltage of the boost-mode bootstrap capacitor above a second reference voltage during a buck mode of the buck-boost converter circuit;
- and
- an electronic circuit having an input electrically coupled to the converter to receive the converted supply voltage.
Dependencies are inferred from the claim text.