Gate Driving Circuit with Temperature-Adaptive Current Control

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Solution Overview

Problem

Conventional gate driving circuits for semiconductor switching elements face a trade-off between reducing switching loss and switching noise, as they lack the ability to adjust the gate current based on temperature conditions, leading to excessive switching loss or noise when temperature changes occur.

Innovation Solution

A gate driving circuit that includes a temperature detection circuit and a current adjustment circuit, which dynamically adjusts the gate current according to temperature conditions, reducing switching loss when it's high and noise when it's low, by controlling the gate resistance and voltage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the gate current is increased to reduce switching loss, then switching loss decreases, but switching noise increases

Engineering Contradiction:
Improveswitching lossVSAvoidswitching noise
Core Design Contradiction:
Loss of energyVSObject-generated harmful factors

Solution Approach 1:

The gate driving circuit dynamically adjusts the gate current based on temperature conditions. The current adjustment circuit modifies the gate current magnitude in response to temperature detection, enabling the system to adapt between reducing switching loss (at higher temperatures) and suppressing switching noise (at lower temperatures), thus resolving the static trade-off contradiction.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the parameter of gate current magnitude based on temperature conditions. By detecting temperature and adjusting the gate current parameter accordingly, the system optimizes the balance between switching loss and switching noise, transforming a fixed parameter system into a variable one that adapts to operational conditions.

Inventive Principle:
Principle #35Parameter changes

2Object-generated harmful factors

If the gate current is decreased to reduce switching noise, then switching noise decreases, but switching loss increases

Engineering Contradiction:
Improveswitching noiseVSAvoidswitching loss
Core Design Contradiction:
Object-generated harmful factorsVSLoss of energy

Solution Approach 1:

The gate driving circuit dynamically adjusts the gate current based on temperature conditions. The current adjustment circuit modifies the gate current magnitude in response to temperature detection, enabling the system to adapt between reducing switching loss (at higher temperatures) and suppressing switching noise (at lower temperatures), thus resolving the static trade-off contradiction.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the parameter of gate current magnitude based on temperature conditions. By detecting temperature and adjusting the gate current parameter accordingly, the system optimizes the balance between switching loss and switching noise, transforming a fixed parameter system into a variable one that adapts to operational conditions.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If a conventional temperature detection and protection circuit is used, then abnormal temperature protection is achieved, but control of gate current adjustment according to temperature conditions is not performed

Engineering Contradiction:
Improvetemperature protectionVSAvoidgate current adjustment capability
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The gate driving circuit integrates multiple functions into a single system: temperature detection, gate current adjustment, and protection operations. The current adjustment circuit and detection circuit work together to provide both adaptive gate current control for optimization and protection capabilities, eliminating the need for separate protection circuits and enabling dual functionality.

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

Solution Approach 2:

The invention merges the temperature detection function with the gate current control function. The detection circuit and current adjustment circuit are integrated within the gate driving circuit, combining protection and optimization capabilities into a unified system that simultaneously provides both functions.

Inventive Principle:
Principle #5Merging (Combining)

4Loss of energy

If the switching speed is increased to reduce switching loss, then switching loss decreases, but switching noise increases

Engineering Contradiction:
Improveswitching lossVSAvoidswitching noise
Core Design Contradiction:
Loss of energyVSObject-generated harmful factors

Solution Approach 1:

The gate driving circuit dynamically adjusts the gate current based on temperature conditions. The current adjustment circuit modifies the gate current magnitude in response to temperature detection, enabling the system to adapt between reducing switching loss (at higher temperatures) and suppressing switching noise (at lower temperatures), thus resolving the static trade-off contradiction.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the parameter of gate current magnitude based on temperature conditions. By detecting temperature and adjusting the gate current parameter accordingly, the system optimizes the balance between switching loss and switching noise, transforming a fixed parameter system into a variable one that adapts to operational conditions.

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 allows for simultaneous reduction of switching loss and noise, with a reduced component count compared to conventional systems, enabling precise adjustment of the gate current and improving the reliability of the switching element.

Implementation Method 1

a detection voltage Ve obtained from a gate current Ic flowing from a constant current source via a shunt resistor to the gate of the switching element

Methodology Applied
Scientific EffectTemperature detection via voltage measurement: Ohm's Law

Data Source

PatentEP2955825B1Gate driving circuit
Publication Date: 2019.08.28 MITSUBISHI ELECTRIC CORP
  • EP2955825B1 patent drawingFigure 1
  • EP2955825B1 patent drawingFigure 2
  • EP2955825B1 patent drawingFigure 3

AI summary

A temperature detection circuit (4) for detecting a temperature of a switching element (1), a current source (5) for causing a forward current to flow to the temperature detection circuit (4), an amplifier circuit (9) for amplifying a forward voltage of the temperature detection circuit (4), a current adjustment circuit (12) for adjusting a magnitude of a gate current to the switching element (1) on the basis of an output voltage of the amplifier circuit (9), and a drive circuit (7, 8) for receiving an external signal and turning ON/OFF the switching element (1), are included. The magnitude of the gate current caused to flow from the current adjustment circuit (12) to the gate electrode of the switching element (1) is adjusted on the basis of a change in a magnitude of the forward voltage corresponding to a change in the temperature of the temperature detection circuit (4).