Power rail regulator to regulate DC rail voltage and output current

A power regulators system and method is disclosed. In one embodiment, a power regulator system (10) is provided and includes at least one power supply (16) each configured to convert a DC rail voltage to a DC load voltage. The DC load voltage can be less than the DC rail voltage and can be provided to power at least one electronic component. The system (10) also includes a power rail regulator (12) configured to generate the DC rail voltage based on an input voltage and to regulate a magnitude of the DC rail voltage to vary between a minimum voltage magnitude and a maximum voltage magnitude and to regulate a variable magnitude of an output current. The DC rail voltage and the output current can be regulated based on load requirements associated with the at least one electronic component (18).

BACKGROUND

Computer systems may include different loads that require varied voltages. The varied voltages may require power converters to take a common bus or rail voltage and convert it to meet the required input power characteristics for the load. As an example, a given computer system can include a power rail, such as a 12 volt power rail. The power rail can be used as a bus to power system components, or it can be regulated down to provide the power requirements of a specific load, such as some combination of 3.3 volts and/or 5 volts.

DETAILED DESCRIPTION

FIG. 1illustrates an example embodiment of a power regulator system10. The power regulator system10can be included in any of a variety of electronic systems, such as computer systems and/or portable electronic devices. The power regulator system10includes a power rail regulator12that is configured to convert an AC voltage VACgenerated from an AC voltage source14to a DC output rail voltage VOUT—RAIL. As an example, the AC voltage VACcan be a 120 volt, 60 Hz, AC voltage, such as received from a wall outlet. However, it is to be understood that the AC voltage source14in the example ofFIG. 1could instead be implemented as a DC voltage source, such that the power rail regulator12converts a DC voltage to the DC output rail voltage VOUT—RAIL. In the example ofFIG. 1, the power rail regulator12also generates an output current IOUT—RAIL.

The power regulator system10also includes a plurality N of power supplies16, where N is a positive integer. Each of the power supplies16can be configured as buck, boost, and/or buck boost converters to convert the DC output rail voltage VOUT—RAILto DC voltages VDC—1through VDC—N, respectively. As an example, the DC voltages VDC—1through VDC—Ncan be any combination of voltage magnitudes, such as 3.3 volts and/or 5 volts. The DC voltages VDC—1through VDC—Nare each provided to power respective one or more electronic components18, demonstrated in the example ofFIG. 1as ELECTRONIC COMPONENT(S)1through ELECTRONIC COMPONENT(S) N. As an example, the electronic component(s)18can include a variety of electronic components, such as computer circuits, chips, and/or processors. In addition, the power regulator system10also includes one or more rail power components20, such as fans and/or motors, that are each powered directly from the DC output voltage VOUT—RAIL.

In the example ofFIG. 1, the power rail regulator12is configured to vary the magnitude of the DC output rail voltage VOUT—RAILand the output current IOUT—RAIL, such as based on load requirements associated with the electronic component(s)18and/or the rail power component(s)20. As an example, the power rail regulator12can monitor a feedback signal, demonstrated in the example ofFIG. 1as the signal CURR_FDBK, that is indicative of the power consumption of the electronic component(s)18and/or the rail power component(s)20. As an example, the signal CURR_FDBK could be implemented to provide current consumption information associated with the one or more electronic component(s)18and/or the one or more rail power component(s)20. Alternatively, the signal CURR_FDBK could provide other information indicative of the power consumption of the electronic component(s)18and/or the rail power component(s)20. Thus, the power rail regulator12can generate the DC output rail voltage VOUT—RAILas having a magnitude that varies from a minimum magnitude to a maximum magnitude, demonstrated in the example ofFIG. 1as voltages VMINand VMAX, respectively. Therefore, the DC output rail voltage VOUT—RAILcan be generated at lower magnitudes during light load conditions, such as to substantially maximize the efficiencies of the power supplies16during light load conditions.

As an example, the power rail regulator12can be configured to regulate the DC output rail voltage VOUT—RAILand the output current IOUT—RAILin different regions that each span a range of output power associated with the power rail regulator12. In each of the regions, one of the DC output rail voltage VOUT—RAILand the output current IOUT—RAILcan be alternately held at a substantially constant magnitude. For example, the power rail regulator12can generate the DC output rail voltage VOUT—RAILat a substantially constant minimum magnitude VMINin a first region spanning a range of output power from zero to a first predetermined output power and can generate the DC output rail voltage VOUT—RAILat a substantially constant maximum magnitude VMAXin a last region spanning a range of output power from a second predetermined output power to a maximum power.

FIG. 2illustrates an example embodiment of a graph50of output voltage and output current for a power rail regulator. The power rail regulator can correspond to the power rail regulator12in the example ofFIG. 1. Therefore, reference is to be made to the example ofFIG. 1in the following description of the example ofFIG. 2.

The graph50includes a first vertical axis on which the output current IOUT—RAILis demonstrated in amps and a second vertical axis on which the DC output rail voltage VOUT—RAILis demonstrated in volts. The graph50also includes a horizontal axis on which the output power of the power rail regulator12is demonstrated in watts. In the example ofFIG. 2, the output current IOUT—RAILis plotted as a solid line, while the DC output rail voltage VOUT—RAILis plotted as a dotted line.

The graph50demonstrates the regulation of the DC output rail voltage VOUT—RAILand the output current IOUT—RAILin three regions52,54, and56, demonstrated as REGION1, REGION2, and REGION3. Each span a range of the output power associated with the power rail regulator12. The first region52is demonstrated as spanning zero watts to approximately 180 watts. Therefore, the first region52can define a substantially light load operating region of the power supply system10. In the first region52, the DC output rail voltage VOUT—RAILis regulated at a substantially constant magnitude of approximately 6 volts. As an example, the 6 volts could be the minimum voltage magnitude VMINassociated with the power rail regulator12. As the load requirements of the electronic components18and/or the rail power components20increase through the first region52, the power rail regulator12increases the output current IOUT—RAILto meet the required power.

The second region54is demonstrated as spanning approximately 180 watts to approximately 360 watts. The second region54can be defined based on a programmable setpoint for the output current IOUT—RAIL, such as provided by a signal CURR_SET demonstrated in the example ofFIG. 1. As an example, the programmable setpoint for the output current IOUT—RAILcan be based on tradeoffs between conductive losses and converter efficiency gains. In the second region54, the output current IOUT—RAILis regulated at a substantially constant magnitude of approximately 30 amps. As the load requirements of the electronic components18and/or the rail power components20increase through the second region54, the power rail regulator12increases the DC output rail voltage VOUT—RAILto meet the required power.

The third region56is demonstrated as spanning approximately 360 watts to approximately 600 watts, which could be a maximum power output associated with the power rail regulator12. The third region56can be defined based on the DC output rail voltage VOUT—RAILincreasing to the maximum magnitude VMAX. Thus, in the third region56, the DC output rail voltage VOUT—RAILis regulated at a substantially constant magnitude of approximately 12 volts (e.g., the maximum magnitude VMAX). As the load requirements of the electronic components18and/or the rail power components20increase through the second region54, the power rail regulator12increases the output current IOUT—RAILto meet the required power, up to the approximately maximum output power of the power rail regulator12(e.g., 600 watts).

Power supplies that generate a DC output voltage from a higher DC source voltage typically operate less efficiently as the difference between the higher DC source voltage and the DC output voltage increases. The power rail regulator12thus regulates the DC output rail voltage VOUT—RAILand the output current IOUT—RAILmore efficiently than typical power rail regulators. Specifically, during light load conditions, the power rail regulator12operates in the first region52, thus generating the DC output rail voltage VOUT—RAILat the substantially constant minimum magnitude VMIN. As a result, the power supplies16generate the DC voltages VDC—1through VDC—Nfrom a source voltage of approximately 6 volts in the example ofFIG. 2, as opposed to a higher voltage that is suitable for any load conditions. Accordingly, the power rail regulator12is much more efficient during light load conditions associated with the electronic components18and/or the rail power components20.

In addition, the current setpoint that defines the second region54is programmable based on the signal CURR_SET. Thus, the operation of the power rail regulator12can be flexibly adjusted to balance conductive losses of the electronic components18and/or the rail power components20relative to the efficiency gains of the power supplies16. In addition, the power rail regulator12can be configured to regulate the DC output rail voltage VOUT—RAILand the output current IOUT—RAILin more or less than just three regions. As an example, the power rail regulator12can be configured to regulate the DC output rail voltage VOUT—RAILand the output current IOUT—RAILin any integer of regions, with the DC output rail voltage VOUT—RAILbeing regulated at the minimum voltage VMINin the first region and at the maximum voltage VMAXin the last region. As another example, the power rail regulator12can be configured to regulate the DC output rail voltage VOUT—RAILand the output current IOUT—RAILin just two regions, with the DC output rail voltage VOUT—RAILbeing regulated at the minimum voltage VMINin the first region and at the maximum voltage VMAXin the last region, with the magnitude of the output current IOUT—RAILvarying accordingly in both regions. Furthermore, the power rail regulator12could be configured to regulate the DC output rail voltage VOUT—RAILin step-wise voltage increments, such as to approximate a substantially constant current, or even to include a negative slope of the output current IOUT—RAIL.

Therefore, the signal CURR_SET can be implemented to set multiple current setpoints in intermediate regions, thus allowing further flexibility of the operation of the power rail regulator12. Furthermore, it is to be understood that the regions52,54, and56are not limited to maintaining one of the DC output rail voltage VOUT—RAILand the output current IOUT—RAILat a constant magnitude, but could instead regulate both of the DC output rail voltage VOUT—RAILand the output current IOUT—RAILat variable magnitudes in each of the regions. Thus, the power rail regulator12can be configured in a variety of ways.

While it is described herein that the regions52,54, and56span a range of output power associated with the power rail regulator12, it should be noted that the regions52,54, and56can instead be considered as defined by the magnitude of the output current IOUT—RAILbased on the relationship of the output current IOUT—RAILwith the DC output rail voltage VOUT—RAILand based on the DC output rail voltage VOUT—RAILbeing substantially constant in the first and last regions52and56. Thus, as described herein, it is to be understood that the definitions of the boundaries between the regions52,54, and56can be based on output power or the magnitude of the output current IOUT—RAIL.

FIG. 3illustrates an example of a computer system100that can be employed to implement systems and methods described herein, such as based on computer executable instructions running on the computer system. The computer system100can be implemented on one or more general purpose networked computer systems, embedded computer systems, routers, switches, server devices, client devices, various intermediate devices/nodes and/or stand alone computer systems. Additionally, the computer system100can be implemented as part of a network analyzer or associated design tool running computer executable instructions to perform methods and functions, as described herein.

The computer system100includes a processor102and a system memory104. A system bus106couples various system components, including the system memory104to the processor102. Dual microprocessors and other multi-processor architectures can also be utilized as the processor102. The system bus106can be implemented as any of several types of bus structures, including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures. The system memory104includes read only memory (ROM)108and random access memory (RAM)110. A basic input/output system (BIOS)112can reside in the ROM108, generally containing the basic routines that help to transfer information between elements within the computer system100, such as a reset or power-up.

The computer system100can include a hard disk drive114, a magnetic disk drive116, e.g., to read from or write to a removable disk118, and an optical disk drive120, e.g., for reading a CD-ROM or DVD disk122or to read from or write to other optical media. The hard disk drive114, magnetic disk drive116, and optical disk drive120are connected to the system bus106by a hard disk drive interface124, a magnetic disk drive interface126, and an optical drive interface134, respectively. The drives and their associated computer-readable media provide nonvolatile storage of data, data structures, and computer-executable instructions for the computer system100. Although the description of computer-readable media above refers to a hard disk, a removable magnetic disk and a CD, other types of media which are readable by a computer, may also be used. For example, computer executable instructions for implementing systems and methods described herein may also be stored in magnetic cassettes, flash memory cards, digital video disks and the like. A number of program modules may also be stored in one or more of the drives as well as in the RAM110, including an operating system130, one or more application programs132, other program modules134, and program data136.

A user may enter commands and information into the computer system100through user input device140, such as a keyboard, a pointing device (e.g., a mouse). Other input devices may include a microphone, a joystick, a game pad, a scanner, a touch screen, or the like. These and other input devices are often connected to the processor102through a corresponding interface or bus142that is coupled to the system bus106. Such input devices can alternatively be connected to the system bus106by other interfaces, such as a parallel port, a serial port or a universal serial bus (USB). One or more out device(s)144, such as a visual display device or printer, can also be connected to the system bus106via an interface or adapter146.

The computer system100may operate in a networked environment using logical connections148to one or more remote computers150. The remote computer148may be a workstation, a computer system, a router, a peer device or other common network node, and typically includes many or all of the elements described relative to the computer system100. The logical connections148can include a local area network (LAN) and a wide area network (WAN).

When used in a LAN networking environment, the computer system100can be connected to a local network through a network interface152. When used in a WAN networking environment, the computer system100can include a modem (not shown), or can be connected to a communications server via a LAN. In a networked environment, application programs132and program data136depicted relative to the computer system100, or portions thereof, may be stored in memory154of the remote computer150.

By way of further example, the computer system100includes a power regulator system156. The power regulator system156can be configured substantially similar to the power regulator system10in the example ofFIG. 1. Specifically, the power regulator system156can include a power rail regulator, such as the power rail regulator12in the example ofFIG. 1, that can generate a DC output rail voltage from an AC voltage generated by an AC voltage source158. The power rail regulator can vary the magnitude of the DC output rail voltage and an associated output current, such as based on load requirements associated with other electronic components in the computer system100. As an example, the power rail regulator can regulate the DC output rail voltage and the associated output current in a number of regions that each span a range of output power of the power rail regulator, such as demonstrated in the example ofFIG. 2. Thus, additional power supplies that generate DC voltages that power the other electronic components in the computer system100can operate more efficiently, such as during light load conditions.

In view of the foregoing structural and functional features described above, an example methodology will be better appreciated with reference toFIG. 4. While, for purposes of simplicity of explanation, the methodology ofFIG. 4is shown and described as executing serially, it is to be understood and appreciated that the present invention is not limited by the illustrated order, as some embodiments could in other embodiments occur in different orders and/or concurrently from that shown and described herein.

FIG. 4illustrates an example embodiment of a method150for providing power. At152, an AC voltage is converted to a DC rail voltage. At154, the DC rail voltage is converted to at least one DC load voltage that each powers at least one electronic component. At156, a magnitude of the DC rail voltage is regulated at a minimum voltage magnitude through a first range of output power and at a maximum voltage magnitude through a second range of the output power based on load requirements associated with the at least one electronic component. At158, a magnitude of an output current associated with the DC rail voltage is adjusted through the first range of the output power and through the second range of the output power based on the load requirements associated with the at least one electronic component.

What have been described above are examples of the invention. It is, of course, not possible to describe every conceivable combination of components or methodologies for purposes of describing the invention, but one of ordinary skill in the art will recognize that many further combinations and permutations of the invention are possible. Accordingly, the invention is intended to embrace all such alterations, modifications, and variations that fall within the scope of this application, including the appended claims.