Abstract: An architecture is described for performing memory management in a virtualization environment. Multiple levels of caches are provided to perform address translations, where at least one of the caches contains a mapping between a guest virtual address and a host physical address. This type of caching implementation serves to minimize the need to perform costly multi-stage translations in a virtualization environment.

Abstract: A system, in certain embodiments, may include a server power supply having a modular chassis having dimensions standardized across a plurality of different servers. The dimensions may be configured to fit the modular chassis uniformly within receptacles of the plurality of different servers. A method of manufacture, in certain embodiments, may include providing a server power supply having a modular chassis with dimensions standardized across a plurality of different servers. Again, the dimensions may be configured to fit the modular chassis uniformly within receptacles of the plurality of different servers.

Abstract: Disclosed is a power supply module for use in an electronic system having redundant power supply modules connected to a power bus. The power supply module includes an output filter. The output filter is configured, upon insertion of the power supply module into the electronic system during operation of the electronic system, to limit reverse current flow into the power supply module from the power bus for a period of time until steady state voltage conditions exist on the power bus. The output filter is configured to then remove the current-limiting, leaving an output inductor-capacitor filter.

Abstract: A power supply comprises an alternating current-to-direct current converter (ADC) and an input signal adapted to couple to an output signal of another power supply. The output signal is indicative of the operational status of the other power supply. The power supply further comprises logic coupled to the ADC that receives the input signal and causes an output current threshold to be increased when the output signal from the other power supply indicates that the other power supply has experienced a failure.

Abstract: An integrated circuit includes a phase-locked-loop with fast clock synchronization recovery. A phase frequency detector is configured to receive a system clock signal and a feedback clock signal and to generate a comparison signal. A clock generator is configured to general a first clock signal based on the comparison signal, and an internal clock signal. A controller coupled to the clock generator and configured to deliver a mesh clock signal to a global clock mesh. A synchronizer coupled to the control logic and configured to generate a feedback clock signal to the phase frequency detector. The mesh clock signal is provided from the global clock mesh to the synchronizer. Advantages of the invention include the ability to operate the integrated circuit in a sleep state with a slow clock rate and then quickly recover to an operational clock rate.

Abstract: Methods and apparatuses are disclosed that may allow elimination of isolation devices for redundant power supplies while mitigating the undesirable effects of their elimination.

Abstract: A power meter receives an output-voltage and a current-indicative signal generated by at least one power supply of an electronic system. The output voltage powers at least one electronic component of the electronic system. The current-indicative signal indicates a percentage of a maximum output current capacity at which the power supply is producing current. From the output voltage and the current-indicative signal, the power meter determines the input power received by the power supply.

Abstract: A system may include a plurality of loads, a plurality of power supplies adapted to provide power to the loads, and control logic coupled to the power supplies. The control logic may determine whether output current from at least one of the power supplies to a load is below a lower threshold and, if so, may cause at least one of the power supplies to be disabled.

Abstract: A DC-to-DC converter comprises a first power module, at least a second power module coupled to the first power module, and a protection circuit coupled to the first and second power modules. The protection circuit causes a system power good signal to be at a state indicative of a power problem when the protection circuit detects that a switching node of one of the power modules has ceased switching.

Abstract: The specification may disclose a switching power supply operated in a discontinuous current power factor corrected mode, having multiple boost circuits or boost modules, and controlled by a digital signal processor. The digital signal processor may implement a control scheme whereby the duty cycle of the switching signals applied to the boost modules may be controlled, in part, by the amount of power delivered to the load in the previous half cycle of the source voltage. In another aspect, an output voltage correction to the switching signals may be applied at the end of each half cycle, which may result in voltage correction at twice the source frequency.

Abstract: The specification may disclose a switching power supply operated in a discontinuous current power factor corrected mode, having multiple boost circuits or boost modules, and controlled by a digital signal processor. The digital signal processor may implement a control scheme whereby the duty cycle of the switching signals applied to the boost modules may be controlled, in part, by the amount of power delivered to the load in the previous half cycle of the source voltage. In another aspect, an output voltage correction to the switching signals may be applied at the end of each half cycle, which may result in voltage correction at twice the source frequency.

Abstract: An alternating current to direct current switching power supply, with power factor correction, and having an integrated rectifying bridge and boost circuit.

Abstract: The specification discloses a power factor corrected switching power supply. The power factor corrected switching power supply may utilize, in whole or in part, leakage inductance of a common-mode choke to provide boost inductance.

Abstract: The specification discloses an alternating current to direct current switching power supply, with power factor correction, and having an integrated rectifying bridge and boost circuit that results in the use of fewer power semiconductor devices in the rectification and boosting process. The use of fewer power semiconductor devices translates into a power supply with greater efficiency and/or smaller size. More particularly, the diodes in a rectifying bridge that typically conduct power back to the alternating current power source are paralleled by power MOSFETs, and the boost inductor is coupled between the source and the modified bridge. Charging of the boost inductor takes place through the power MOSFETs, resulting in only a two MOSFET power dissipation. Discharging of the boost inductor (and therefore supplying power not the load) takes place through two diodes, and therefore two forward power losses (as opposed to three diodes and three forward conduction losses associated in the related art).

Abstract: A method and apparatus for providing uninterrupted DC power for network nodes. The uninterrupted DC power is derived from modular, stackable uninterruptible power supplies that fit within the housing of the network node. Because the battery of the uninterruptible power supply is charged from a DC output of a main power supply, only one AC/DC power converter is required. A high degree of efficiency is therefore obtained.

Abstract: An efficient fan drive circuit to drive a variable fan used in a power supply of a personal computer system. The fan drive circuit uses a diode to establish the minimum fan speed during operation in the normal temperature range. The bleeder resistor normally coupled between the fan and a negative output voltage is removed and replaced with a current source. The current source also serves to shut down the power supply if the fan is not operating properly or is not installed. A shut down circuit remains to shut down the power supply when excessive temperature occurs, or when the current source detects that the fan is malfunctioning or not installed.

Abstract: A power converter including a complementary regeneration circuit for eliminating oscillations and conserving leakage energy to increase the efficiency of a flyback power converter. The complementary regeneration circuit includes a regeneration capacitor, a regeneration switch, a diode and appropriate timing circuitry to switch the regeneration capacitor in and out of the circuit at the appropriate times. Due to the operation of the regeneration switch, the capacitance of the regeneration capacitor is much larger than a typical snubber/clamp capacitor, so that it overdamps the circuit eliminating voltage overshoot typically appearing across the primary switch. The regeneration capacitor charges with regeneration energy and drives negative current into the primary inductor, holding the voltage across the primary switch constant when the secondary current goes to zero.

Abstract: A differential input comparator for controlling the output voltage of an AC adapter to track the voltage of a rechargeable battery during trickle charge. An output voltage sensing circuit typically used to regulate the AC adapter output voltage at a maximum level is modified to regulate the output voltage at a minimum DC voltage approximately equivalent to a fully discharged battery plus a nominal voltage level. The differential input comparator is coupled to a current limiter coupled in the charge path of the battery and to the sense signal to provide a separate current path used to modify the voltage level of the sense signal. The differential input comparator regulates the voltage across the current limiter to the nominal voltage level by controlling the AC adapter output voltage through the sense signal during trickle charge of the battery.

Abstract: An AC adapter including an automatic battery voltage selection circuit that senses which battery pack is installed in an electronic device and regulates the AC adapter output voltage at an appropriate level. A battery voltage selection signal providing circuit provides the battery voltage selection signal indicative of the particular battery pack present. An output voltage sensor senses the output voltage of the AC adapter and provides a proportional sense signal to a feedback circuit which controls the AC adapter output. A switching circuit coupled to the output voltage sensor and to the battery voltage selection signal providing circuit modifies the sense signal depending upon the state of the battery voltage selection signal, so that the AC adapter output voltage is regulated at an appropriate level for the particular battery pack installed.