Parallel Gate Driver Circuit With Separated References

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Solution Overview

Problem

Existing gate driver circuits struggle to provide balanced and efficient control of semiconductor switches connected in parallel, leading to unbalanced voltage and current distributions, which can result in increased conduction losses and reduced performance.

Innovation Solution

A power switching assembly comprising two gate driver circuits with separate internal supply nodes and reference nodes, each equipped with a buffer capacitor, ensures independent and balanced gate drive loops by maintaining separate reference potentials and using buffer capacitors to manage transient voltages, thereby preventing harmful compensation currents.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If multiple semiconductor switches are connected in parallel to increase current capacity, then the current handling capability is improved, but unbalanced voltage and current distributions occur between the switches

Engineering Contradiction:
Improvecurrent capacityVSAvoidvoltage and current distribution balance
Core Design Contradiction:
PowerVSManufacturing precision

Solution Approach 1:

The gate driver circuit is segmented into multiple independent driver circuits (first driver circuit, second driver circuit, etc.), each controlling a respective semiconductor switch. Each driver circuit has its own internal supply node and reference node, creating independent control channels that prevent cross-interference and ensure balanced current distribution among parallel switches.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Each driver circuit is provided with localized buffer capacitors (first buffer capacitor, second buffer capacitor, etc.) connected between its internal supply node and reference node. These local capacitors provide individual transient current compensation for each switch, ensuring uniform switching characteristics and balanced current sharing across all parallel-connected switches.

Inventive Principle:
Principle #3Local quality

2Device complexity

If a single gate driver output signal is used to drive multiple parallel semiconductor switches, then the device complexity is reduced, but harmful compensation currents occur due to transient voltage drops

Engineering Contradiction:
Improvegate driver configurationVSAvoidcompensation currents
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The single gate driver is segmented into multiple independent driver circuits, each with separate reference nodes. This segmentation prevents the formation of compensation current loops that would occur with a shared reference node, as each driver now has its own independent reference potential and buffer capacitor, eliminating the harmful circulating currents.

Inventive Principle:
Principle #1Segmentation

3Device complexity

If reference nodes are shared between driver circuits, then the device complexity is reduced, but transient voltage drops cause unbalanced switching

Engineering Contradiction:
Improvereference node configurationVSAvoidswitching symmetry
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The shared reference node is segmented into multiple separate reference nodes (first reference node, second reference node, etc.), each dedicated to a specific driver circuit. This segmentation isolates the reference potentials from each other, preventing transient voltage drops in one circuit from affecting others, thereby ensuring symmetric and balanced switching across all parallel semiconductor switches.

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

This solution enables independent control of each semiconductor switch, reducing conduction losses and ensuring symmetric switching by decoupling gate drive loops from transient voltage drops, thus improving the overall efficiency and balance of parallel-connected semiconductor switches.

Implementation Method 1

A first buffer capacitor is electrically connected between the first internal supply node and the first reference node. A second buffer capacitor is electrically connected between the second internal supply node and the second reference node.

Methodology Applied
Scientific EffectCapacitance: Capacitance

Data Source

PatentEP4346102A1Gate driver circuit and power switching assembly with gate driver circuit
Publication Date: 2024.04.03 INFINEON TECH AUSTRIA AG
  • EP4346102A1 patent drawingFigure 1A~1B
  • EP4346102A1 patent drawingFigure 2
  • EP4346102A1 patent drawingFigure 3

AI summary

A power switching assembly (900) includes a first driver circuit (110) and a second driver circuit (120). The first driver circuit (110) is supplied via a first internal supply node (VDD1) and a first reference node (VSS1) and drives a first gate signal. The second driver circuit (120) is supplied via a second internal supply node (VDD2) and a second reference node (VSS2) and drives a second gate signal. The first gate signal and the second gate signal are in phase. The first reference node (VSS1) and the second reference node (VSS2) are separated. A first buffer capacitor (131) is electrically connected between the first internal supply node (VDD1) and the first reference node (VSS1). A second buffer capacitor (132) electrically connected between the second internal supply node (VDD2) and the second reference node (VSS2).