VOLTAGE CONVERTER WITH COMBINED CAPACITIVE VOLTAGE DIVIDER, BUCK CONVERTER AND BATTERY CHARGER
First Claim
1. A voltage converter, comprising:
- a first capacitor coupled between a reference node and a first output node wherein said first output node develops a first output voltage;
a second capacitor coupled between an input node and either one of said reference and first output nodes;
a third capacitor having first and second ends;
a switch circuit which couples said first and second ends of said third capacitor to said reference node and said first output node, respectively, in a first state of a pulse width modulation signal, and which couples said first and second ends of said third capacitor to said first output node and said input node, respectively, in a second state of said pulse width modulation signal;
an inductor having a first end coupled to said first end of said third capacitor and having a second end forming a second output node providing a second output voltage;
a fourth capacitor coupled between said reference node and said second output node; and
a controller which controls duty cycle of said pulse width modulation signal between said first and second states to regulate said second output voltage to a predetermined output voltage level, and which provides a voltage control signal to control voltage of an input voltage provided on said input node to maintain said first output node between a predetermined minimum battery voltage level and a predetermined maximum battery voltage level.
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Accused Products
Abstract
A voltage converter including a capacitive voltage divider combined with a buck converter and battery charger. The converter includes four capacitors, a switch circuit, an inductor and a controller. The capacitors form a capacitor loop between an input node and a reference node and include a fly capacitor controlled by the switch circuit, which is controlled by a PWM signal to half the input voltage to provide a first output voltage on a first output node, and to convert the first output voltage to the second output voltage via the inductor. The controller controls the PWM signal to regulate the second output voltage, and provides a voltage control signal to control the input voltage to maintain the first output node between a predetermined minimum and maximum battery voltage levels. A battery charge path is coupled to the reference node and battery charge mode depends upon the battery voltage.
166 Citations
21 Claims
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1. A voltage converter, comprising:
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a first capacitor coupled between a reference node and a first output node wherein said first output node develops a first output voltage; a second capacitor coupled between an input node and either one of said reference and first output nodes; a third capacitor having first and second ends; a switch circuit which couples said first and second ends of said third capacitor to said reference node and said first output node, respectively, in a first state of a pulse width modulation signal, and which couples said first and second ends of said third capacitor to said first output node and said input node, respectively, in a second state of said pulse width modulation signal; an inductor having a first end coupled to said first end of said third capacitor and having a second end forming a second output node providing a second output voltage; a fourth capacitor coupled between said reference node and said second output node; and a controller which controls duty cycle of said pulse width modulation signal between said first and second states to regulate said second output voltage to a predetermined output voltage level, and which provides a voltage control signal to control voltage of an input voltage provided on said input node to maintain said first output node between a predetermined minimum battery voltage level and a predetermined maximum battery voltage level. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. An electronic device, comprising:
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a combined buck converter and capacitor voltage divider, comprising; a first capacitor coupled between a reference node and a first output node wherein said first output node develops a first output voltage; a second capacitor coupled between an input node and either one of said reference and first output nodes; a third capacitor having first and second ends; a switch circuit which couples said first and second ends of said third capacitor to said reference node and said first output node, respectively, in a first state of a pulse width modulation signal, and which couples said first and second ends of said third capacitor to said first output node and said input node, respectively, in a second state of said pulse width modulation signal; an inductor having a first end coupled to said first end of said third capacitor and having a second end forming a second output node providing a second output voltage; a fourth capacitor coupled between said second output node and said reference node; and a controller which controls duty cycle of said pulse width modulation signal between said first and second states to regulate said second output voltage to a predetermined output voltage level, and which provides a voltage control signal to control voltage of an input voltage provided on said input node to maintain said first output voltage between a predetermined minimum battery voltage level and a predetermined maximum battery voltage level; a power source connector for receiving a source voltage provided to said input node and for externally providing said voltage control signal; and functional circuitry which receives said first and second output voltages and which performs functions of the electronic device. - View Dependent Claims (11, 12, 13, 14, 15)
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16. A method of controlling an input voltage and for converting the input voltage to first and second output voltages, comprising:
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providing the input voltage to an input node relative to a reference node; coupling a capacitor loop between the input node, the reference node, and a first output node developing the first output voltage; toggling coupling of a fly capacitor based on duty cycle of a pulse width modulation signal, wherein the fly capacitor is charged between the input node and the first output node and discharged between the first output node and a reference node; selectively toggling a first end of an inductor between the first output node and the reference node based on the duty cycle of the pulse width modulation signal; coupling the second end of the inductor to a second output node which develops a second output voltage; controlling the duty cycle of the pulse width modulation signal to regulate the second output voltage to a predetermined level; and controlling a voltage level of the input voltage to maintain the first output voltage between a predetermined minimum battery voltage level and a predetermined maximum battery voltage level. - View Dependent Claims (17, 18, 19, 20, 21)
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Specification