Juniper Networks, Inc.

Silicon Graphics, Incorporated

Dilip A Amin

Ross Heitkamp

Michael Armstrong

Chang Hong Wu

A voltage regulator having a regulator output operating at a predetermined output voltage level is disclosed. The voltage regulator includes a switching regulator that has a first regulated output providing a first output voltage level, where the first output voltage level is approximately equal to the predetermined output voltage. The first regulated output is coupled to the regulator output. The voltage regulator includes a linear regulator that has a second regulated output providing a second output voltage level, where the second output voltage level is less than the first output voltage level. The second regulated output is coupled to the first regulated output such that the voltage at the regulator output is maintained at approximately the predetermined output voltage level by operation of the switching regulator until the regulator output falls below the second output voltage level at which time the regulator output is maintained at approximately the predetermined output voltage level by operation of either the linear regulator or both the linear regulator and the switching regulator.

Combined linear and switching voltage regulator

A space-efficient power supply powers a system and is housed in a small area of the system. The components of the power supply are designed to reduce heat generation and be aerodynamically efficient. Reduced heat generation reduces the need for air space around the power supply for cooling air, thus allowing the power supply to be housed in a small space. And because the components are aerodynamically efficient, space requirements are further reduced. In one embodiment the power supply is used in a system to power secondary power supplies. The secondary power supplies provide isolated power to components of a system, such as a communications system in an equipment box. In another embodiment, the power supply is used in an equipment box to power communications equipment distributed in the equipment box.

Space-efficient power supply systems and methods with minimal heat generation

A voltage sequencing circuit powers-up electrical systems by sequentially enabling a series of power supply lines to the electrical system. After each power supply line is enabled, the voltage sequencing circuit waits a pre-programmed delay time before enabling the next power supply line. The delay time allows the newly enabled power supply line to settle. Additionally, the voltage sequencing circuit constantly monitors previously enabled power supply lines while continuing to enable the remaining power supply lines. If any of the previously enabled lines fail, the voltage sequencing circuit disables the power supply line before reinitiating a complete power-up sequence.

Voltage sequencing circuit for powering-up sensitive electrical components

A system and method for minimizing disruption of operating power in a high-availability computer as new power supplies are hot-inserted. In the preferred embodiment, the high-availability computer includes a plurality hot-plug power supplies, a logic circuit system, and a power distribution system for distributing operating power from the power supplies to the logic circuit system. Preferably, the output capacitance of each power supply is significantly less than the total capacitance of the logic circuit system and the power distribution system, such that, as each power supply is hot-inserted into the computer, only a minute amount of electric charges will be transferred from the power distribution system and the logic circuit system to the power supply. As a small amount of charge transfer would generate only a small voltage drop, any glitch produced by hot-insertion would be significantly reduced. In order to compensate for an increased glitch recovery time attributable to the increased capacitance, the power supply of the present invention may use a poly-phase voltage regulator. Further, the computer system of the present invention may include a timer for indicating to the service person that the power supply of the present invention has been successfully installed on an operating computer.

Hot-plug power supply for high-availability computer systems

An ultra low drop out power regulator is described. The power regulator may be used, for example, where a dynamically fast, and electrically clean power supply at the point of use is required. The power regulator is provided as a single part with two input voltages. The higher voltage input drive the output stage so that ultra low drop out is achieved. The disclosed regulator is therefore more efficient, resulting in less heat dissipation. The regulator is packaged in a stand up package thereby reducing board space. By use of a stand up package, air flow to other components is not blocked.

Growing community of inventors

San Jose, CA, United States of America

Dilip A Amin