Dell USA L P

Dell Products Inc.

Benchmarq Microelectronics, Inc.

Deli U.s.a., L.p.

Alan E Brown

Farzad Khosrowpour

Steven J Lash

James A Bilich

Barry K Kates

Frank P Helms

Joseph Daniel Mallory

N Deepak Swamy

Joseph A Vivio

Matthew Bruce Mendelow

Jeff Savage

Vahid Samiee

Nathan Wiscombe

Joshua Titus

Louis E Cano

A comparison circuit for comparing the desired voltage levels of electronic components and for disabling the supply of power to those components if the desired voltage levels are not equivalent. The comparison circuit receives the desired voltage level indication signals and provides a signal indicating whether the desired voltage levels are equivalent. If the desired voltage levels are not equivalent, the comparison circuit provides a signal indicating non equivalency to a power supply, wherein the power supply is disabled from supplying power so as not to damage the computer components from receiving power at a non allowable voltage level. The comparison circuit also provides an output signal indicative of an equivalent voltage level to the desired voltage levels if the desired voltage levels are equivalent. A power supply converter supplies power to the components at a voltage level as indicated by the output signal. The comparison circuit can be implemented in a computer system such as a multiprocessor computer system where each processor module provides a desired voltage level indication signal to the comparison circuit.

Electronic component desired voltage level comparison

A restart circuit for a power supply of an electronic system such as a computer system for delaying the restart of the power supply until a power supply output is in compliance with a specified parameter. In one embodiment, the specified parameter is a particular threshold voltage level and the power supply output is in compliance when it is less than the particular threshold voltage level. In another embodiment of a restart circuit, the specified parameter is a rate of decay in a voltage level and the power supply output is in compliance when it is decaying at a rate less than the predetermined rate. In one embodiment, delaying the restart of the power supply permits components of the system to be reset when the voltage level of the power supply output is in a known state.

Power supply restart circuit

A comparison circuit for comparing the desired voltage levels of electronic components and for disabling the supply of power to those components if the desired voltage levels are not equivalent. The comparison circuit receives the desired voltage level indication signals and provides a signal indicating whether the desired voltage levels are equivalent. If the desired voltage levels are not equivalent, the comparison circuit provides a signal indicating non equivalency to a power supply, wherein the power supply is disabled from supplying power so as not to damage the computer components from receiving power at a non allowable voltage level. The comparison circuit also provides an output signal indicative of an equivalent voltage level to the desired voltage levels if the desired voltage levels are equivalent. A power supply converter supplies power to the components at a voltage level as indicated by the output signal. The comparison circuit can be implemented in a computer system such as a multiprocessor computer system wherein each processor module provides a desired voltage level indication signal to the comparison circuit.

A switching voltage regulator and a method of providing transition control therein. The regulator includes: (1) a modulation circuit for generating switching signals, (2) first and second switches coupled between a regulator output of the voltage regulator and respective first and second voltage inputs, control inputs of the switches coupled to the modulation circuit to allow the switches to couple the regulator output alternately between the voltage inputs as a function of a state of the switching signals and (3) a regulator output power waveform transition control circuit coupled to the control inputs of the switches for generating an override signal to the control inputs under a specified condition, the override signal causing the switches to couple the regulator output to the first voltage input independent of the state of the switching signals.

Active output power waveform transition control for a step-down voltage

A personal computer includes a DC to DC converter which employs a dual function capacitive energy storage device at the output rail of the converter. The energy storage device provides both a transition control function and a bulk or output function. In this manner, the size and expense of a separate bulk capacitor is advantageously avoided. The converter includes a switching transistor coupled to a bulk inductor. The switching transistor exhibits a high frequency switching rate which is sufficiently high to permit the inductor to directly replenish the capacitive energy storage device thus enabling the converter to withstand both major and minor load fluctuations without loss of voltage regulation at the output rail.

Computer system with improved DC to DC power conversion employing

By separating a power regulator at a point between the output inductor and the output capacitor of the regulator, the capacitive output section can be located close to a processor (or other load device) while the remaining portion of the regulator can be placed in another location away from the processor. With the capacitive output section located close to the processor and valuable system board space can be saved.

Sectionalized power regulator separated between an output inductor and

A discharge control circuit for a power supply switching converter that, in response to a cessation of current from an AC power source, makes conductive a main switching element of the switching converter to discharge the bulk filter capacitor through the main switching element to a charge level that meets safety standards. The discharge control unit includes a current limiting circuit for limiting the discharge current through the main switching element in which the rate of rise of the discharge current is controlled with the use of an RC circuit. The discharge control unit also includes a state machine that activates the current limiting circuit in response to a cessation of the modulation mode of the switching converter. The discharge control circuit also includes a reset circuit for placing the state machine in a known state during the startup of the switching converter.

Bulk filter capacitor discharge in a switching power supply

Electronic systems such as computer systems often utilize regulated voltage to meet system requirements such as accurate logic levels and predictable performance. A switching voltage regulator implements a pulse width modulator using two timer circuits, such as 555 class timers, configured in a master/slave relationship to provide modulation signals to control current flow to a voltage regulator output filter. The switching regulator employing the pulse width modulator may be arranged as a buck switching voltage regulator, and the pulse width modulator alternately turns switches in a switch bank ON (low impedance current path) and OFF (high impedance current path) to facilitate current flow to energy storage elements configured as an averaging filter. Furthermore, additional timer circuitry may be implemented to ensure nonoverlap of current flow in the switches. Additionally, feedback signals may provide error feedback to the pulse width modulator to facilitate voltage regulation, and a signal source, such as a processor, may be utilized to programmably control a voltage regulator output voltage by controlling pulse width duty cycles and/or periods.

Voltage supply regulation using master/slave timer circuit modulation

A power supply includes a power factor correction converter and a controller that disables a power factor correction converter when the power supply is operating in a low power mode, when the power factor correction converter is not needed. The controller of the power factor correction converter performs control operations as directed by a control program executing in a computer or processor in some embodiments. In other embodiments, the control operations are directed by an automatic sequence self-directed by a state machine or other sequencer according to a self-analysis.

System and method for reducing power losses by gating an active power

A multiphase direct current (DC) regulator using voltage mode control to provide a regulated voltage and provide current equalization between the phases. The regulator includes a voltage mode control circuit receiving an indication voltage level indicative of the amount of current supplied from the DC power source to an inductor of a first phase. The voltage mode control circuit providing a first control signal dependent upon the indication voltage level to a switching circuit that provides a switching signal to a switch. The switch controlling the amount of current from the DC power source supplied to a second inductor of a second phase according to the switching signal.

Voltage mode control for a multiphase DC power regulator

Method and apparatus for providing a regulated, direct current (DC) output voltage for use in computers. An unregulated voltage source is regulated by a power converter of the present invention that produces the regulated voltage reliably, inexpensively, and without requiring heat sinks or auxiliary fans. In a preferred embodiment, the power converter includes a buck regulator and a control circuit. The control circuit includes a resistor-divider feedback loop connected to the output of the buck regulator in order to provide a feedback voltage. The feedback voltage is supplied to an error amplifier which compares the feedback voltage to an internal reference voltage and produces an output that is the amplified difference between the two voltages. The amplified output is then provided to a frequency modulation (FM) port of a multipurpose timer. As a result, the timer can control and modulate the frequency and pulse width of the buck regulator.

Low cost power converter for a computer

A circuit for determining and reporting the energy consumed by an electronic device having a microprocessor and power supply lines for supplying power to the device is disclosed. The circuit comprises a voltage divider connected for sensing the voltage across the power supply lines and generating a voltage signal indicative of the sensed voltage. A current sense resistor is connected in series with a power supply line for sensing the current passing through the power supply lines and generating a current signal indicative of the sensed current. An analog multiplier is connected for receiving and computing the product of the voltage and current signals, and for generating a power signal indicative of the product of the voltage and current signals, the power signal being indicative of the power consumed by the device. A proportional voltage-to-frequency converter is connected for receiving the power signal and for generating primary signal pulses at a frequency proportional to the voltage level of the power signal, each of which pulses is indicative that a predetermined quantity of energy has been consumed by the device. An opto-coupler, connected to the converter, is responsive to generation of the primary signal pulse for reporting to the microprocessor a secondary signal pulse indicating that a predetermined quantity of energy has been consumed by the device.

System for reporting computer energy consumption

Method and a system for automatically and securely performing computer power up and logon functions. In one embodiment, the system is implemented in a personal computer ('PC') and comprises a central processing unit ('CPU'), a card reader for reading data encoded on user identification cards 'swiped' therethrough, and a power supply capable of constantly providing a low power, or 'flea power,' signal to various components of the PC, including the CPU and card reader, for enabling a soft power startup of the PC. Responsive to detection of a user identification card being swiped through a slot on the card reader, the card reader reads information for identifying the user, in particular, a user ID and security code, encoded on the card and transmits the read information to the CPU. If the CPU determines that the user identified by the user ID is authorized to access the PC, the PC is powered up and the user is logged onto the PC using the data read from the card. Thereafter, if at any time while the user is logged onto the computer, a determination is made that there has been no I/O activity for a predetermined amount of time, the user is automatically logged off of the PC and the PC is powered down. Similarly, if during operation of the PC, the user ID card is again swiped through the reader, the user will be logged off of the PC and the PC will be powered down.

Method and apparatus for automatically implementing computer power on

A surge modification circuit controls surge current flows which may occur when a computer and AC adapter are connected. The surge current flows are controlled using active circuitry since passive circuitry, which is in place continuously, sustains large uninterrupted heating power losses in the order of watts that are wasted over time. In one embodiment, a surge modification circuit in an AC adapter includes a control element that operates as a power analog switch with a slow transition time to reduce the steepness of a surge wavefront resulting from the connection of the output terminals of the AC adapter to a computer while the AC adapter is energized. In a second embodiment, a surge modification circuit in an AC adapter employs a pair of power converter control circuits including a main power converter control circuit for performing the power conversion and a sensing power converter control circuit for determining whether the AC Adapter is connected to a computer and informing the main power converter control circuit of the connection status so that the main power converter is disabled when the computer is not attached. In some embodiments, an optoelectronic coupler is advantageously used to communicate a message indicative of the status of a connection between the AC Adapter and the computer. The optoelectronic coupler transfers the status message using optical isolation to maintain a barrier of isolation supplied by the transformer between the computer, mutually isolating AC and DC power.

System and method for controlling current flow in an AC adapter

A determinate power source control for an integrated circuit (10) includes a variable voltage regulator (16), which is operable to receive a supply voltage on the input thereof and output a regulated voltage for input to the integrated circuit (10). A voltage adjustment circuit (22) is operable to generate a voltage adjustment value V.sub.ADJ for input to the voltage regulator (16) to determine the voltage output thereby. In a determinate operating mode, the voltage adjustment circuit (22) varies the V.sub.ADJ value to cause the regulator (16) to vary the regulated output voltage to the integrated circuit (10). For each value, the operating speed of the integrated circuit (10) is determined and this information stored in a table (24). Thereafter, the voltage adjustment circuit (22) is placed in an operating mode wherein the voltage adjustment value associated with the optimum operating speeds of the integrated circuit (10) is selected and input to the voltage regulator (16). The voltage adjustment circuit (22) utilizes an on-chip ring oscillator (38) to generate a series of pulses which are input to a counter (48). The counter (48) and ring oscillator (38) are operated for a predetermined amount of time with reference to crystal oscillator (30), and then this value latched into latch (52).

Growing community of inventors

Georgetown, TX, United States of America

Alan E Brown