Multi-cell DC-DC Converter Diagnostic Circuit for Defective Cell Detection

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Solution Overview

Problem

Multi-cell DC-DC converters face performance degradation and increased output oscillations due to defective cells, especially when cells are integrated on the same semiconductor chip, where manufacturing dispersions can lead to short-circuits, rendering the entire converter unusable.

Innovation Solution

A diagnostic circuit is implemented to individually test each cell, detect defective cells, deactivate them, and memorize their location, allowing the converter to continue operating with healthy cells while reconfiguring clock signals to minimize output oscillations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multiple conversion cells are integrated on the same semiconductor chip to improve conversion ratio and reduce size, then productivity and integration are improved, but reliability deteriorates due to manufacturing dispersions causing short-circuits in defective cells

Engineering Contradiction:
Improveconversion ratioVSAvoidcell functionality
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The converter is divided into multiple independent conversion cells, each with its own switch and energy storage element. This segmentation allows individual cells to be tested and deactivated independently, preventing a single defective cell from rendering the entire converter unusable while maintaining high conversion ratios through parallel/series configurations.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A diagnostic circuit is implemented to perform preliminary testing of each conversion cell before full operation. The diagnostic circuit individually tests cells by measuring output voltages and comparing them to expected values, identifying defective cells in advance and deactivating them before they can cause significant performance degradation or short-circuits.

Inventive Principle:
Principle #10Preliminary action

2Device complexity

If defective cells are not detected and deactivated, then device complexity is reduced, but performance deteriorates due to significant degradation and increased output oscillations

Engineering Contradiction:
Improveconverter structureVSAvoidconverter performance
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The diagnostic circuit continuously monitors the output voltage of each conversion cell and provides feedback to the control circuit. When a defective cell is detected through voltage measurement and comparison, the control circuit receives feedback and automatically deactivates the defective cell, maintaining converter performance without requiring complex manual intervention or redesign.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3076535B1Dc-dc converter
Publication Date: 2018.06.27 COMMISSARIAT A LENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES
  • EP3076535B1 patent drawingFigure 1~2
  • EP3076535B1 patent drawingFigure 3~4
  • EP3076535B1 patent drawingFigure 5

AI summary

The invention relates to a DC-DC converter comprising: a plurality of conversion cells (cell1, cell2) connected in parallel and/or in series, each cell comprising at least one switch (T1, T2, T3, T4) and at least one passive energy storage element (C); and a diagnostic circuit (BIST) adapted to individually test the cells (cell1, cell2) in order to detect possible defective cells, to deactivate the defective cells, and to memorize the location of the defective cells.