Switching dc-dc power supply to control output voltage
AssigneeDell Products L.P.
InventorsBrent A. McDonald, John J. Breen
Life of this patent
Estimating the term…
Abstract
In a DC-DC converter, a technique for sensing current supplied to a load and establishing an output voltage that conforms to a predetermined load line. The current carried by an inductor is sensed and used to control the duty cycle of the voltage applied to the inductor, thereby controlling the output voltage. A current sensing circuit includes a feedback network. A pole attributable to the feedback network cancels a zero attributable to the inductor so that a control voltage is developed that varies substantially linearly with the load current.
Claims26
A switching DC-DC converter circuit comprising:
- a DC-voltage input node;
- an output node for providing an output voltage that varies in response to a load current;
- an intermediate node;
- an inductor coupled between the output node and the intermediate node;
- a first switch coupled between the DC-voltage input node and the intermediate node, the first switch operable to vary a duty cycle of a voltage applied to the intermediate node in response to a control signal;
- a current sense circuit having an input coupled to the inductor and a current sense >11 output that varies substantially linearly in response to a current flowing through the inductor;
- and
- a controller circuit comprising:
- a first controller input coupled to the current sense output;
- a second controller input coupled to the output node;
- and
- at least one controller output for providing the control signal to the first switch, wherein the control signal causes the duty cycle to vary so that the output voltage varies in response to the current flowing through the inductor.
A method of sensing current through an inductor of a DC-DC converter enabled to control an output voltage of the DC-DC converter, the method comprising:
- measuring the current through the inductor by measuring a voltage signal across the inductor, wherein the voltage signal is linearly proportional to the current through the inductor;
- measuring the output voltage of the DC-DC converter;
- and
- adjusting a duty cycle of the DC-DC converter circuit to vary the measured output voltage to an adjusted output voltage in response to the measured current through the inductor and the measured output voltage, wherein the adjusted output voltage varies in response to the current flowing through the inductor.
In a DC-DC converter having an input node, an output node and an intermediate node, a method of controlling a DC output voltage at the output node, the method comprising:
- ensing a current flowing through an inductor that is coupled between the intermediate node and the output node so as to develop a current sense signal;
- developing a control signal in response to the current sense signal and in response to the DC output voltage at the output node;
- and
- varying the duty cycle of a voltage applied to the intermediate node so that the DC output voltage varies in response to the current flowing through the inductor.
A DC-DC converter for providing a DC output voltage that is controllably variable in response to a local current, the DC-DC converter comprising:
- a DC voltage input node;
- a DC voltage output node for providing the load current and the DC output voltage;
- an intermediate node;
- a switch coupled between the input node and the intermediate node;
- an inductance coupled between the intermediate node and the output node;
- and
- means coupled to the inductance for providing a control signal that varies substantially linearly with respect to the load current and for applying to the control signal to the switch so that the duty cycle of the switch, and the magnitude of the DC output voltage, are determined by the control signal.
A computer system comprising:
- a processor;
- a memory coupled to the processor;
- and
- a power supply system for providing power to the processor, wherein the power supply system comprises a switching DC-DC converter circuit comprising:
- a DC-voltage input;
- a DC-voltage output that varies in response to a load current;
- a switch comprising a switch input, a switch output and a control signal input, wherein the switch input is coupled to the DC-voltage input node and the switch output is coupled to an inductor, wherein the control signal determines duty cycle of a signal applied to the inductor, wherein the inductor is coupled between the switch output and the DC-voltage output;
- a current sense circuit comprising a current sense input coupled to the inductor to detect a current through the inductor and a current sense output that varies substantially linearly with the current sense input;
- and
- a controller circuit comprising:
- a first controller input coupled to the current sense output;
- a second controller input coupled to the DC-voltage output;
- and
- at least one controller output for providing the control signal to the switch, wherein the control signal causes the duty cycle to vary the DC-voltage output, in response to the current flowing through the inductor.
Dependencies are inferred from the claim text.