Voltage Regulator Double-Loop Control for Current Equalization

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Solution Overview

Problem

Voltage regulators in computing systems face challenges such as uneven load distribution, reduced efficiency, reliability issues, and temperature hotspots due to parasitic resistance and inductance, which can destabilize the system and lead to unpredictable output voltages.

Innovation Solution

A double-control-loop regulation system with an inner local sense loop and an outer remote sense loop, decoupled from each other, is implemented to dynamically adjust the output voltage and compensate for parasitic effects, along with adaptive voltage positioning (AVP) to ensure target voltage is maintained across the compute domain.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If multiple voltage regulators are used to power a compute domain, then power supply capacity is improved, but load distribution becomes uneven and efficiency decreases

Engineering Contradiction:
Improvepower supply capacityVSAvoidefficiency
Core Design Contradiction:
PowerVSLoss of energy

Solution Approach 1:

The patent implements a control circuit that continuously monitors the load current of each voltage regulator and uses feedback signals to dynamically adjust the operation of individual regulators. This feedback mechanism enables the system to respond to changing load conditions and redistribute power delivery in real-time, ensuring optimal efficiency while maintaining adequate power supply capacity.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system transitions from static power distribution to dynamic load balancing by enabling voltage regulators to adapt their operation based on real-time load conditions. The control circuit allows regulators to dynamically adjust their contribution to the total load, optimizing efficiency as operating conditions change while maintaining sufficient power supply capacity.

Inventive Principle:
Principle #15Dynamics

2Power

If multiple voltage regulators are used to power a compute domain, then power supply capacity is improved, but reliability decreases due to uneven load distribution

Engineering Contradiction:
Improvepower supply capacityVSAvoidsystem reliability
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The control circuit employs feedback mechanisms to monitor load current and operational status of each voltage regulator, enabling real-time detection of uneven load distribution. This feedback allows the system to identify and correct reliability issues before they manifest as failures, ensuring consistent and reliable power delivery across the compute domain.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system implements self-balancing capabilities where voltage regulators automatically adjust their operation based on monitored load conditions. This self-service mechanism ensures that no single regulator is overloaded, preventing failure points and maintaining high system reliability without requiring external intervention.

Inventive Principle:
Principle #25Self-service

3Device complexity

If traditional single control loop is used, then device complexity is low, but output voltage becomes unpredictable due to parasitic effects

Engineering Contradiction:
Improvecontrol loop complexityVSAvoidoutput voltage precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent divides the single control loop into two separate control loops: an inner loop for local voltage sensing and regulation, and an outer loop for remote voltage sensing and compensation. This segmentation allows each loop to specialize in specific functions, with the inner loop handling fast transient response and the outer loop compensating for parasitic effects, thereby improving output voltage precision without excessive complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary control structure between the voltage regulator and the load, consisting of two nested control loops. This intermediary system acts as a mediator that actively compensates for parasitic resistance and inductance effects, ensuring precise output voltage regulation despite the presence of parasitic elements in the power delivery path.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Stability of the object's composition

If decoupled double control loop is implemented, then output voltage stability is improved, but device complexity increases

Engineering Contradiction:
Improveoutput voltage stabilityVSAvoidcontrol circuit complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The control circuit is segmented into two functionally distinct but decoupled loops: an inner loop for rapid local regulation and an outer loop for slower remote compensation. This segmentation allows each loop to operate independently at its optimal speed and precision, improving overall voltage stability while managing complexity through functional separation rather than monolithic design.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The decoupled control loops operate at different frequencies and time scales, with the inner loop providing high-frequency transient response and the outer loop providing lower-frequency steady-state regulation. This periodic action at different levels ensures comprehensive voltage stability without requiring the entire system to operate at maximum complexity simultaneously.

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP4369585A1Current equalization and reconfigurable double control loop for voltage regulators
Publication Date: 2024.05.15 INTEL CORP
  • EP4369585A1 patent drawingFigure 1
  • EP4369585A1 patent drawingFigure 2
  • EP4369585A1 patent drawingFigure 3

AI summary

Embodiments herein relate to controlling one or more voltage regulators (VRs) to avoid excessive degradation when a VR increases it current output to supply a hot spot in a compute domain. In one approach, a group of VRs supply current to the domain and each VR's load is monitored to detect an increase in current. A digital controller can reduce the target voltage and/or switching frequency for a VR experiencing an increase in current to equalize the current outputs among the VRs, within a tolerance. In another aspect, a double control loop is used to control a VR. An inner control loop regulates the output of the VR relative to a target voltage and an outer control loop detects the load and adjusts the target voltage and/or switching frequency to avoid excessive degradation.