Voltage Converter Dynamic Coil Current Limiting

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Solution Overview

Problem

Hysteretic switching converters often exhibit significant voltage ripple in their output voltage due to their switching mode, which affects the efficiency and stability of voltage conversion in portable electronic devices.

Innovation Solution

A voltage converter design that selectively limits the coil current to predetermined values, using a control module to generate control signals for a switch coupled in series with the coil, allowing the converter to operate in phases that optimize energy storage and release, thereby reducing output voltage ripple.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If hysteretic switching mode is used for voltage conversion, then the converter can be implemented simply and power consumption is reduced, but output voltage ripple increases significantly

Engineering Contradiction:
Improveconverter implementation simplicityVSAvoidoutput voltage ripple
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The patent implements dynamic adjustment of the coil current peak value based on operating conditions. The control module selectively limits the coil current to different predetermined peak values depending on the output voltage level and load conditions, making the converter adaptable to varying requirements while maintaining simple hysteretic switching operation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the current limiting parameter dynamically by selecting from multiple predetermined current values. The control module monitors output voltage and adjusts the peak current limit accordingly, using lower current values when output voltage is stable (reducing ripple) and higher values when voltage drops (maintaining power delivery).

Inventive Principle:
Principle #35Parameter changes

2Power

If peak coil current is increased to maintain output voltage under heavy load, then power delivery capability is improved, but output voltage ripple increases

Engineering Contradiction:
Improvepower delivery capabilityVSAvoidoutput voltage ripple
Core Design Contradiction:
PowerVSObject-generated harmful factors

Solution Approach 1:

The patent implements dynamic current limiting where the peak coil current value is adjusted based on real-time output voltage conditions. The control module selects from multiple predetermined current values, using higher values only when necessary to maintain output voltage during heavy load conditions, while using lower values during normal operation to minimize ripple.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the operating parameter (peak current limit) based on system state. By monitoring output voltage and selecting appropriate current limits from a set of predetermined values, the system optimizes the balance between power delivery capability and output voltage stability.

Inventive Principle:
Principle #35Parameter changes

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

This approach effectively minimizes output voltage ripple, improves efficiency, and reduces power dissipation by adapting the peak current value based on load conditions, enhancing the performance and stability of voltage conversion.

Implementation Method 1

The energy may be stored in a magnetic field, for example by a coil or a transformer

Methodology Applied
Scientific EffectMagnetic field energy storage: Electromagnetic Induction

Implementation Method 2

The energy may be stored in a magnetic field, for example by a coil or a transformer, or in an electric field, for example by a capacitor

Methodology Applied
Scientific EffectElectric field energy storage: Capacitance

Data Source

PatentEP2871762B1Voltage converter and method for voltage conversion
Publication Date: 2019.02.27 AUSTRIAMICROSYSTEMS AG
  • EP2871762B1 patent drawingFigure 1A~1B
  • EP2871762B1 patent drawingFigure 2A~2B
  • EP2871762B1 patent drawingFigure 3A~3B

AI summary

A voltage converter comprises a coil (11), a switch (12) coupled in series to the coil (11) and a control module (20) that is coupled to a control terminal of the switch (12). The control module (20) is designed to provide a control signal (SNG) to the control terminal of the switch (12) such that a coil current (IC) flowing through the coil (11) is selectively limited to a selected current value of at least two predetermined current values (ILA, ISM).