Phase Controller Load-Current Sensing for Light-Load Converters

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Solution Overview

Problem

Accurate measurement of load-current in switching converters under light load conditions is challenging due to the wide range of load-current ratings, which affects efficiency.

Innovation Solution

A multi-phase switching converter system with a phase controller that integrates current signals to generate a voltage-output representing load-current magnitude, using a transconductance amplifier and capacitor to determine ON-time for optimal efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional current measurement methods are used to cover the full rated load-current range, then the measurement range is sufficient, but the measurement precision deteriorates under light load conditions

Engineering Contradiction:

Improveload-current measurement precisionVSAvoidload-current measurement range

Core Design Contradiction:

Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent implements dynamic current measurement range switching by detecting light load conditions and automatically selecting between first and second current measurement ranges. The phase controller dynamically adjusts the measurement configuration based on actual load conditions, enabling high precision measurement under light loads while maintaining adequate measurement capability across the full rated range.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the measurement parameters (current measurement range) based on operating conditions. By switching between different measurement ranges (first range for normal loads, second range for light loads), the system adapts the measurement sensitivity to match the actual load level, thereby achieving high precision measurement across varying load conditions.

Inventive Principle:

Principle #35Parameter changes

2Loss of energy

If the switching converter operates under light load conditions, then energy efficiency is improved, but accurate measurement of load-current becomes more difficult

Engineering Contradiction:

Improveconverter efficiencyVSAvoidload-current measurement accuracy

Core Design Contradiction:

Loss of energyVSMeasurement precision

Solution Approach 1:

The patent employs feedback mechanisms where the phase controller continuously monitors the load current and uses this information to adjust the measurement configuration. The feedback loop enables the system to detect light load conditions and switch to the appropriate measurement range, ensuring accurate measurement while maintaining efficient operation under light loads.

Inventive Principle:

Principle #23Feedback

3Adaptability or versatility

If a wide load-current measurement range is implemented, then the converter can handle all operating conditions, but the measurement accuracy under light load deteriorates

Engineering Contradiction:

Improveoperating condition coverageVSAvoidlight load measurement accuracy

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent segments the current measurement range into multiple distinct ranges (first current measurement range and second current measurement range). Each segment is optimized for specific operating conditions, with the second range providing high precision for light loads and the first range covering normal operating loads. This segmentation allows the system to maintain both wide adaptability and high precision measurement accuracy.

Inventive Principle:

Principle #1Segmentation

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables accurate determination of load-current for efficient operation under light loads by adjusting ON-time and switching frequency, enhancing converter efficiency.

Implementation Method 1

The phase controller integrates the current signal in the analog continuous form to generate a voltage-output representing a magnitude of the load-current

Methodology Applied

Scientific EffectTransconductance amplification:

Implementation Method 2

using a transconductance amplifier and capacitor to determine ON-time for optimal efficiency

Methodology Applied

Scientific EffectCapacitance: Capacitance

Data Source

PatentUS20250357861A1Phase controller of a switching converter measuring load-current under light load

Publication Date: 2025.11.20 NINGBO AURA SEMICON CO LTD

AI summary

A multi-phase switching converter provided according to an aspect of the present disclosure includes a power stage and a phase controller, and provides a regulated supply voltage from an input voltage in a light load condition. The power stage receives a phase control signal and drives an inductor to cause flow of an inductor-current according to the phase control signal, wherein a load-current of the multi-phase switching converter is formed from the inductor-current. The phase controller receives a current signal from the power stage at a pin, the current signal being in an analog continuous form to represent the inductor-current in the power stage. The phase controller integrates the current signal in the analog continuous form to generate a voltage-output representing a magnitude of the load-current, and determines the magnitude of load-current based on the voltage-output.