A control system and method for simultaneously regulating the operation of a plurality of different types of switching power converters. The system utilizes in regulating the power converters sampled data and nonlinear feedback control loops.

Power converter circuitry and method

A synthetic ripple regulator for a DC-DC converter generates an auxiliary voltage waveform that effectively replicates the waveform ripple current through an output inductor, and uses the auxiliary voltage waveform to control toggling of a hysteretic comparator. In a non-limiting implementation, a transconductance amplifier monitors the voltage across the inductor, and supplies an inductor voltage-representative current to a ripple waveform capacitor, so as to produce the auxiliary voltage waveform. Using the replicated inductor current for ripple regulation results in low output ripple, input voltage feed forward, and simplified compensation.

Synthetic ripple regulator

An enterprise-wide sharing arrangement uses a semantic abstraction, called a security assessment, to share security-related information between different security products, called endpoints. A security assessment is defined as a tentative assignment by an endpoint of broader contextual meaning to information that is collected about an object of interest. Its tentative nature is reflected in two of its components: a fidelity field used to express the level of confidence in the assessment, and a time-to-live field for an estimated time period for which the assessment is valid. Endpoints may publish security assessments onto a security assessment channel, as well as subscribe to a subset of security assessments published by other endpoints. A specialized endpoint is coupled to the channel that performs as a centralized audit point by subscribing to all security assessments, logging the security assessments, and also logging the local actions taken by endpoints in response to security threats.

Enterprise security assessment sharing

A power supply system includes multiple power converter phases. A controller (e.g., a processor device) monitors energy delivery for each of multiple power converter phases that supply energy to a load. The controller analyzes the energy delivery associated with each of the multiple power converter phases to identify an imbalance of energy delivered by the multiple power converter phases to the load. Based on the analyzing and detection of an imbalance condition, the controller modifies a future order of activating the multiple power converter phases for powering the load. Accordingly, a single phase of a multiphase switching power converter may be prevented from becoming overloaded while delivering energy to power the load.

Power supply and controller circuits

A multiphase DC/DC converter with voltage-mode hysteretic control and instantaneous current sharing functionality method and circuit. The disclosed method and circuit provides independent output voltage regulation and phases current regulation for the converter in two separate loops; one of which is concerned with voltage regulation preferably hysteretic regulation and the other which is concerned with phase current regulation. In one embodiment, each phase in the DC/DC converter is driven by a frequency divided signal derived directly from the output voltage ripple so that each phase has a switching frequency equal to the output voltage ripple frequency divided by the number of paralleled phase. In another embodiment, only the phase that carries the smallest current among a set of phases will be turned ON in each switching cycle to supply power to the output, avoiding multiple switching. Current sharing and regulation is achieved without shortening the ON time and with no multiple switching in any cycle.

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Control method and circuit to provide voltage and current regulation for multiphase DC/DC converters

A system and method provides virtual ripple signal generation for use in voltage regulation applications. Some switch-mode power converters or voltage regulators use output signal ripple to effect voltage regulation. A virtual ripple generator provides this type of voltage regulator with a virtual ripple signal comprising an offset component responsive to actual load voltage, but with a generated AC ripple component of arbitrary magnitude that is independent of actual output signal ripple. Unlike the actual output ripple signal, the generated AC ripple component is not dependent on implementation specifics, such as circuit board layout or output capacitor ESR, and may have its gain set independent of the offset component. The generated AC ripple component is synchronized to the inductor switching actions of the voltage regulator and thus reflects actual inductor phase switching in single and multi-phase regulation applications. Virtual ripple signal generation can include output (load) voltage droop compensation.

Virtual ripple generation in switch-mode power supplies

A ripple-mode controller provides reliable operation in multi-phase power supply circuits, over a variety of operating conditions. Cross-phase blanking allows the controller to preserve the desired phase relationship between the switching pulses its provides to the different output phases, and permits the controller to operate each output phase at nearly 100% duty cycles. Active current sharing compliments blanking operations by adjusting the width of switching pulses the controller provides to one or more of the output phases based on detecting load current imbalances between the different output phases. With active current sharing, the controller prevents one or more output phases from carrying excessive portions of the load current. Further complimenting its operation, the controller may include virtual ripple generation to increase the noise immunity of its ripple-mode regulation.

Self-clocking multiphase power supply controller

A voltage positioning technique allows a power supply controller to more fully exploit active voltage positioning as a way of maintaining supply voltage within the limits defined for an associated electrical load. The supply voltage is allowed to “droop” as a function of load current. Droop may be implemented in linear proportion to load current, or as a discrete droop function once load current exceeds a given threshold. In either case, the droop circuitry of the supply controller implements a bounding function that establishes an accurately known maximum droop voltage magnitude. This maximum droop voltage limit establishes a reliable lower limit for the supply voltage independent of increasing load current. This accurately set lower bound for the droop voltage enables the controller to more aggressively position the supply voltage at the lower voltage limit of the load, which minimizes voltage overshoot and load power consumption.

Bounded power supply voltage positioning

A constant ON-time controller for a buck converter utilizes dual symmetrical ramps. The ramps may be generated artificially or by sensing the voltage across a sense resistor in the output. The ramp may also be generated by sensing the voltage across the “ON” resistance of the low side FET in the switching regulator. A modified output voltage has one of the ramps superimposed and a modified reference voltage has the other ramps superimposed. The modified output voltage and the modified reference voltage are compared to determine when to start the ON-time of the buck converter. The dual ramps reduce, noise susceptibility. The ON-time is stopped in response to charging a capacitor with the regulator input voltage. An offset may also be generated representing the difference between the average output voltage and the reference voltage. The offset is used to generate a modified reference to compensate for the offset.

Constant ON-time controller for a buck converter

A compensated reference voltage for the controller of a buck regulator corrects for offsets and controls the rate at which the output load current can change in response to a change in the reference setting output voltage level of the buck converter. A current source is coupled to a resistor that has one terminal connected to the ground potential of the output voltage. The voltage across this resistor generates a remote reference voltage. A feedback current is generated as a function of the difference between the remote reference voltage and the output voltage. The feedback current is time integrated to form the compensated reference, which is used to control the ON-time of the buck converter.

Terry J. Groom

Papers

Virtual ripple generation in switch-mode power supplies

Self-clocking multiphase power supply controller

Bounded power supply voltage positioning

Constant ON-time controller for a buck converter

Slew rate limited reference for a buck converter