Dual-input power converter and control methods thereof
AssigneeRichtek Technology Corporation
InventorChung-Lung Pai
Life of this patent
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Abstract
A dual-input power converter comprises two power stages using a common low-side element, a first input for coupling a first input voltage to the first power stage, a second input for coupling a second input voltage to the second power stage, and a controller for driving the first and second power stages to convert the first or second input voltage to an output voltage.
Claims24
A dual-input power converter for producing an output voltage, comprising:
- a first input coupled to a first input voltage;
- a second input coupled to a second input voltage, the second input voltage having of a different magnitude than the first input voltage;
- a common low-side switch coupled to a common reference for the first and second input voltages;
- a first high-side switch coupled between the first input and the common low-side switch such that the first high-side switch and the common low-side switch serve as a first power stage;
- a second high-side switch coupled between the second input and the common low-side switch such that the second high-side switch and the common low-side switch serve as a second power stage;
- and
- a controller coupled to the common low-side switch, the first high-side switch, and the second high-side switch for controlling the driving of the first and second power stages to respectively convert the first or second input voltage to the output voltage, the controller driving the common low-side switch, the first high-side switch, and the second high-side switch such that none of their on-duty cycles overlap.
A control method for a dual-input power converter configured with two power stages, each of the power stages having a respective high-side switch coupled to a common low-side switch for producing an output voltage, the control method comprising the steps of:
- providing a first input voltage coupled to the high-side switch of the first power stage;
- providing a second input voltage coupled to the high-side switch of the second power stage, the second input voltage being greater than the first input voltage;
- detecting a magnitude of the first input voltage;
- and
- selectively driving one of the two power stages in correspondence with the magnitude of the first input voltage, wherein the driving step includes:
- a. alternately driving the high-side switch of the first power stage and the common low-side switch for converting the first input voltage to the output voltage responsive to the magnitude of the first input voltage being at least equal to a threshold value;
- or,
- b. alternately driving the high-side switch of the second power stage and the common low-side switch for converting the second input voltage to the output voltage responsive to the magnitude of the first input voltage being less than the threshold value.
A control method for a dual-input power converter configured with two power stages, each of the power stages having a respective high-side switch coupled to a common low-side switch, a first input for coupling a first input voltage to the high-side switch of the first power stage, a second input for coupling a second input voltage to the high-side switch of the second power stage, and an output coupled to the first and second power stages for producing an output voltage, the control method comprising the steps of:
- a. providing the second input voltage to have a different magnitude than the first input voltage;
- b. comparing the output voltage with a reference voltage;
- c. alternately driving the high-side switch of the first power stage and the common low-side switch for converting the first input voltage to the output voltage if the output voltage is at least equal to the reference voltage, the high-side switch of the first power stage and the common low-side switch being driven such that none of their on-duty cycles overlap;
- and
- d. alternately driving the high-side switch of the second power stage and the common low-side switch for converting the second input voltage to the output voltage if the output voltage becomes less than the reference voltage in step b, the high-side switch of the first power stage, the high-side switch of the second power stage, and the common low-side switch each being driven such that none of their on-duty cycles overlap.
A control method for a dual-input power converter configured with two power stages, each of the power stages having a respective high-side switch coupled to a common low-side switch, a first input for coupling a first input voltage to the high-side switch of the first power stage, a second input for coupling a second input voltage to the high-side switch of the second power stage, and an output coupled to the first and second power stages for producing an output voltage, the control method comprising the steps of:
- providing the second input voltage to have a different magnitude than the first input voltage;
- detecting an on-duty time period of the high-side switch in the first power stage;
- alternately driving the high-side switch of the first power stage and the common low-side switch for converting the first input voltage to the output voltage responsive to the on-duty time period being less than a threshold, the high-side switch of the first power stage and the common low-side switch being driven such that none of their on-duty cycles overlap;
- and
- alternately driving the high-side switch of the second power stage for converting the second input voltage to the output voltage responsive to the on-duty time period being greater than the threshold one or more times, the high-side switch of the first power stage, the high-side switch of the second power stage, and the common low-side switch each being driven such that none of their on-duty cycles overlap.
A control method for a dual-input power converter configured with two power stages, each of the power stages having a respective high-side switch coupled to a common low-side switch, a first input for coupling a first input voltage to the high-side switch of the first power stage, a second input for coupling a second input voltage to the high-side switch of the second power stage, and an output coupled to the first and second power stages for producing an output voltage, the control method comprising the steps of:
- providing the second input voltage to have a different magnitude than the first input voltage;
- supplying a clock having a first time interval and a second time interval within each period;
- driving the first power stage for converting the first input voltage to the output voltage during the first time interval, the high-side switch of the first power stage and the common low-side switch being alternately driven to an on-state during the first time interval;
- and
- driving the second power stage for converting the second input voltage to the output voltage during the second time interval, the high-side switch of the second power stage and the common low-side switch being alternately driven to an on-state during the second time interval, the high-side switch of the first power stage, the high-side switch of the second power stage, and the common low-side switch each being driven such that none of their on-duty cycles overlap.
A dual-input power converter for producing an output voltage, comprising:
- a first input coupled to a first input voltage;
- a second input coupled to a second input voltage, the second input voltage having a different magnitude than the first input voltage;
- a switching circuit including a diode coupled to a node, a first switch coupled between the first input and the node, and a second switch coupled between the second input and the node;
- an inductor coupled between the node and an output terminal;
- and
- a controller for operating the switching circuit to alternately drive the first switch on and off during a first time period to cause the inductor to generate the output voltage from the first input voltage and alternately drive the second switch on and off during a second time period to cause the inductor to generate the output voltage from the second input voltage, the diode having a polarity to be conductive when either of the first switch and the second switch is driven off, and the first and second time periods are non-overlapping.
A control method for a dual-input power converter having a first input coupled to a first input voltage, a second input coupled to a second input voltage, a switching circuit including a first switch coupled to the first input, a second switch coupled to the second input, and a third switch coupled between the first and second switches and a common reference for both the first and second input voltages, and an output for producing an output voltage, the control method comprising the steps of:
- providing the second input voltage to have a different magnitude than the first input voltage;
- comparing the output voltage with a reference voltage for producing an error signal;
- comparing the error signal with a first signal for determining a first PWM signal;
- comparing the error signal with a second signal for determining a second PWM signal;
- and
- operating the switching circuit to selectively drive one of the first, second and third switches responsive to the first and second PWM signals for selecting one of the first or second input voltages to convert to the output voltage, operating the switching circuit includes driving the third switch, the first switch, and the second switch such that none of their on-duty cycles overlap.
Dependencies are inferred from the claim text.