Linear Technology Corporation

Randy Guy Flatness

Milton E Wilcox

Xunwei Zhou

Christopher Bruce Umminger

Stephen W Hobrecht

Yuhui Chen

Joey Martin Esteves

Robert C Dobkin

San Hwa Chee

Michael Thomas Engelhardt

Doug Allen LaPorte

Howard H Haensel

A power supply system has an inductive device, a plurality of switching devices for providing connection of the inductive device to input and output nodes and a ground node, and a switch driver circuit for driving the switching devices so as to enable the power supply to operate in a boost mode to increase the input voltage, in a buck mode to decrease the input voltage, and in a solid-state flyback mode to transfer between the boost mode and the buck mode. In the solid-state flyback mode, the switching devices are controlled to provide switching of the inductive device between an input state in which the inductive device is connected between the input node and the ground node, and an output state in which the inductive device is connected between the ground node and the output node.

Switch mode power supply with dynamic topology

A voltage regulator includes an input connectable to a voltage source and an output connectable to a load. The voltage regulator includes an inductor coupled to the output, a switch between the input and the inductor, and a current control loop configured to control the duty cycle of the switch to regulate voltage at the output, wherein the duty cycle being based on both a peak and valley threshold level of current flowing through the inductor.

Advanced current-mode control for switched regulators

Switching regulator circuits and methods are provided for regulating output voltage that include an adjustable minimum peak inductor current level for Burst Mode in current-mode DC-DC regulators. Minimum peak inductor current level control is achieved during Burst Mode by allowing external control for adjusting the burst threshold level. A single pin can be used to distinguish between forced continuous and Burst Mode as well as set the burst threshold level during Burst Mode, or an alternate method of setting a variable burst threshold level can be implemented in which two pins are used, one for selecting the mode of operation and the other for setting the burst threshold level during Burst Mode. The above principles can be applied to both step-up and step-down regulator circuit configurations, as well as both synchronous switching regulators and non-synchronous switching regulators.

Adjustable minimum peak inductor current level for burst mode in current-mode DC-DC regulators

A switched regulator circuit provides step-up and step-down operation in which the level of the input voltage can be greater, equal to, or less than a preset controlled output voltage. A four switch arrangement or two switch arrangement provides buck, boost, and buck-boost regulation under variable frequency valley-peak current mode control. A single sense resistor may be utilized for sensing inductor current during each duty cycle.

Variable frequency current-mode control for switched step up-step down regulators

A switched regulator circuit provides step-up and step-down operation in which the level of the input voltage can be greater, equal to, or less than a preset controlled output voltage. A four switch arrangement or two switch arrangement provides buck, boost, and buck-boost regulation under constant frequency valley-peak current mode control. A single sense resistor may be utilized for sensing inductor current during only a short period during each duty cycle. As an alternative to the sense resistor, the switches themselves can be used to sense current during operation.

Current-mode control for switched step up-step down regulators

A four switch voltage converter is regulated for buck mode and boost mode under constant frequency valley-peak current mode control. Protection circuits are responsive to output voltage and regulator current to prevent excessive current that otherwise might result from abnormally low output voltage short circuit, or spurious switching abnormalities during low duty cycle operation. The regulator control circuit is responsive to the protection circuits to automatically connect a regulator inductor between a common potential and the output to limit current.

Protection for switched step up/step down regulators

The present invention comprises methods and circuits for spread spectrum frequency modulation that reduce peak spectral noise at the outputs or inputs of switching regulators. More specifically, the present invention modulates the operating frequency of the switching regulator in accordance with a frequency modulation waveform having a shape coordinated to a peak noise amplitude waveform that describes the correlation between the operating frequency of a switching regulator and the peak noise amplitude at the regulator's input or output absent spread spectrum frequency modulation.

Methods and circuits for frequency modulation that reduce the spectral noise of switching regulators

A switched regulator circuit provides step-up and step-down operation at high efficiency during light load conditions. Switching loss is reduced in a four switch arrangement by limiting bottom MOSFET switching frequency. The possibility of overcharge in boost mode operation has been avoided by automatically changing to a buck mode operation in response to sensed parameters.

Light load current-mode control for switched step up-step down regulators

A monolithic switching regulator that flexibly distributes its output current among its output channels is provided. The monolithic switching regulator includes one or more additional channels that are externally connected to the output channels for providing additional current partitioning configurations. The external connections may be autosensed or programmed with an additional input pin. A switching logic circuit is provided for distributing the current among the output channels according to their external connections to the additional channels.

Circuits and methods for flexible current partitioning in monolithic switching regulators

Methods for synchronizing non-constant frequency switching regulators with a phase locked loop are disclosed. The methods enable non-constant frequency switching regulators to be synchronized with a phase locked loop to achieve constant frequency operation in steady state while retaining the advantages of non-frequency operation to improve transient response and operate over a wider range of duty cycles. In addition, the methods enable multiple non-constant frequency regulators to be synchronized and operated in parallel to deliver higher power levels to the output than a single switching regulator.

Circuits and methods for synchronizing non-constant frequency switching regulators with a phase locked loop

Multiple phase switching regulators with stage shedding are provided. Multiple phase switching regulators of the present invention have a plurality of single phase switching regulators coupled in parallel to an output capacitor. The plurality of single phase switching regulators supply current to a load at a regulated voltage. A comparator monitors the load current and causes one or more of the single phase switching regulators to be OFF at a low load current threshold. At least one of the single phase switching regulators that remains ON increases its output current so that the multiple phase switching regulator output current continues to match the load current. The present invention may include a second comparator that causes additional single phase switching regulators to be OFF at a second low load current threshold that is lower than the first low load current threshold.

Multiple phase switching regulators with stage shedding

A circuit and method for controlling a switching voltage regulator having (1) a switch including one or more switching transistors and (2) an output adapted to supply current at a regulated voltage to a load including an output capacitor. The circuit and method generates a control signal to turn said one or more switching transistors OFF under operating conditions when the voltage at the output is capable of being maintained substantially at the regulated voltage by the charge on the output capacitor. Such a circuit and method increases the efficiency of the regulator circuit particularly at low average current levels.

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Randy Guy Flatness