Linear Gate Current Buffer for Miller False Turn-On Prevention

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Solution Overview

Problem

Existing power transistor driving systems require large Field Effect Transistors (FETs) to prevent false on events due to Miller capacitance, which occupy significant space and are inefficient.

Innovation Solution

A power switching system utilizing a current buffer configured as a current amplifier, combined with a driver circuit and switch branches, to manage gate voltage and prevent Miller capacitance without requiring large FETs, employing current mirrors and CMOS switches to control the power transistor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If large FETs are used to prevent false on events due to Miller capacitance, then reliability is improved, but area occupied increases significantly

Engineering Contradiction:

Improveprevention of false on eventsVSAvoidspace occupied by FETs

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The driver circuit is divided into multiple independent circuit branches (first circuit branch with first switch, second circuit branch with second switch and current source, third circuit branch with third switch). Each branch independently controls the gate voltage to prevent false turn-on events, eliminating the need for a single large FET and reducing overall area occupation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A current buffer is introduced as an intermediary component between the control circuit and the power transistor gate. The current buffer includes current mirror circuitry that amplifies the control signal current, enabling effective gate voltage control with smaller transistors and reducing the area required while maintaining reliability.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If large FETs are used to create a hard off and prevent false on, then reliability is improved, but device complexity increases

Engineering Contradiction:

Improvehard off capabilityVSAvoidcomplexity of driver circuit

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The driver circuit is segmented into multiple specialized branches, each with specific functions: the first circuit branch provides primary gate drive, the second circuit branch with current source provides hard-off capability, and the third circuit branch provides additional control. This segmentation distributes complexity across modular components rather than requiring a single complex large FET.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The circuit dynamically changes the gate voltage parameter through controlled switching of multiple branches. By adjusting which branches are active and their respective current levels, the circuit achieves hard-off capability and false-on prevention through parameter modulation rather than relying on large FET physical characteristics.

Inventive Principle:

Principle #35Parameter changes

3Area of stationary object

If current buffer with current amplification is used, then area is reduced, but device complexity increases

Engineering Contradiction:

Improvespace utilizationVSAvoidcomplexity of current buffer circuit

Core Design Contradiction:

Area of stationary objectVSDevice complexity

Solution Approach 1:

The current buffer employs current mirror circuitry that creates copies of the control signal current. The current mirrors replicate the input current waveform and transfer it to the output, providing current amplification through a systematic copying mechanism that is area-efficient and maintains signal integrity while adding controlled complexity.

Inventive Principle:

Principle #26Copying

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

Effectively prevents false turn-on events while reducing transistor size, optimizing space utilization and operational efficiency.

Implementation Method 1

a current buffer that is configured as a current amplifier that results in a voltage at the first control terminal

Methodology Applied

Scientific EffectCurrent amplification:

Implementation Method 2

the first circuit branch includes a first switch for opening and closing the first circuit branch; and the second circuit branch includes a second switch and a current source, wherein the second switch is configured to open and close the second circuit branch

Methodology Applied

Scientific EffectElectrical switching:

Implementation Method 3

the second circuit branch includes a second switch and a current source

Methodology Applied

Scientific EffectCurrent generation:

Data Source

PatentUS12587176B2Linear gate current buffer for parallel power device driving applications

Publication Date: 2026.03.24 QORVO US INC

AI summary

Embodiments of a power switching system are disclosed. In some embodiments, the power switching system includes a power transistor, a current buffer, and a driver circuit. The power transistor has a first control terminal, a first transistor terminal, and a second transistor terminal. The current buffer is configured as a current amplifier that results in a voltage at the first control terminal. The current buffer has a second control terminal. The driver circuit has a first circuit branch connected to the second control terminal and a second circuit branch connected to the second control terminal. The first circuit branch includes a first switch for opening and closing the first circuit branch. The second circuit branch includes a second switch and a current source, wherein the second switch is configured to open and close the second circuit branch.