Semiconductor Switch Driver Circuit Without Extra Power Supply

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Solution Overview

Problem

Existing driver circuits for power semiconductor switches, such as IGBTs, require amplification of logic signals due to insufficient voltage and current from programmable logic devices, necessitating expensive fully integrated solutions with additional power supplies.

Innovation Solution

A driver circuit with separate on and off paths, each equipped with a level converter, current amplifier, and output stage, utilizing discrete components to provide the necessary voltages and currents directly to the power semiconductor switch, eliminating the need for an additional power supply.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If a fully integrated drive module is used to amplify logic signals for power semiconductor switch control, then sufficient voltage and current are provided to switch the power device, but additional power supply requirements and high cost are introduced

Engineering Contradiction:
Improveswitching capabilityVSAvoidpower supply requirements
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The driver circuit merges the switch-on path and switch-off path into a unified structure that shares common components and power supply rails. The first and second outputs are generated from the same logic input through complementary transistor pairs, eliminating the need for separate power supplies for each function. This integration reduces system complexity while maintaining full switching capability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The driver circuit uses universal components that serve multiple functions. The first and second transistors in each path serve as both switching elements and amplification stages. The same power supply voltages (first voltage and second voltage) are used for both switch-on and switch-off operations, making the circuit multi-functional without requiring additional power rails.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Ease of manufacture

If discrete components are used instead of fully integrated circuits, then cost is reduced and power supply requirements are simplified, but circuit complexity increases

Engineering Contradiction:
ImprovecostVSAvoidcircuit structure
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The driver circuit is segmented into distinct functional paths: a switch-on path with first transistor and first output, and a switch-off path with second transistor and second output. Each path can be independently analyzed and implemented, making the discrete component design manageable despite the overall circuit complexity. This segmentation allows for modular assembly and testing.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different parts of the circuit have specialized characteristics optimized for their specific functions. The first transistor path is optimized for turn-on operation with appropriate biasing and timing, while the second transistor path is optimized for turn-off operation. This local optimization allows each discrete component to be selected for its specific performance characteristics rather than requiring a single general-purpose integrated solution.

Inventive Principle:
Principle #3Local quality

3Loss of time

If separate switch-on and switch-off paths are implemented, then precise timing control is achieved, but circuit complexity increases

Engineering Contradiction:
Improveswitching timingVSAvoidcontrol paths
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The circuit prepares both switch-on and switch-off paths in advance by providing dedicated transistor pairs and associated components for each function. The first transistor and second transistor are both ready to operate simultaneously when needed, with their respective gate control circuits pre-configured. This preliminary preparation enables precise timing control without adding significant operational complexity during switching events.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2020749B1Driver control for actuating a high performance semiconductor switch
Publication Date: 2014.12.03 SEMIKRON DANFOSS ELEKTRONIK GMBH & CO KG
  • EP2020749B1 patent drawingFigure 1~2
  • EP2020749B1 patent drawingFigure 3a~3b

AI summary

The driver circuit (4) has two outlets (12a,12b) for controlling a power semiconductor switch (2) switched-on by a signal of a voltage (U-vp) against a ground potential (GND) and switched-off by a signal of another voltage (U-vn) against the ground potential. Two inlets (18a,18b) are provided and are controlled by a signal (U-in) of a logic circuit (8) supplied with a third voltage (U-l) and the ground potential.