Logic Level Shifter With Protected Gate Voltage Limits

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Solution Overview

Problem

Existing logic level translators and shifting methods face inefficiencies and potential damage from improper control voltage management, particularly when dealing with varying potential levels.

Innovation Solution

A logic level shifting device utilizing series-connected transistors with controlled DC voltage generators and current mirrors to manage control voltages, ensuring safe operation across different potential levels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If logic level translators are designed to handle varying potential levels, then adaptability is improved, but reliability deteriorates due to potential transistor damage from improper control voltage management

Engineering Contradiction:
Improveadaptability to varying potential levelsVSAvoidtransistor safety and operational reliability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent introduces intermediary control voltage generators that mediate between the input signal and the transistors. These generators produce controlled voltages that are safe for the transistors while still enabling level translation across different potential levels. The first voltage generator produces a first control voltage for the first transistor, and the second voltage generator produces a second control voltage for the second transistor, both acting as protective intermediaries.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent dynamically adjusts control voltage parameters based on the input signal level. The control voltage generators modify their output voltages according to the input potential level, ensuring that the transistors receive appropriate control voltages for each operating condition. This parameter adaptation enables the circuit to handle varying potential levels safely.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If separate voltage generators are used for each transistor, then transistor protection is improved, but device complexity increases

Engineering Contradiction:
Improvetransistor protection from damageVSAvoidcircuit complexity with multiple voltage generators
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the two voltage generators into a single integrated circuit block that produces both control voltages. The first and second voltage generators are implemented within the same level translator device, sharing common components and structure. This merging reduces overall device complexity while maintaining the protective function for both transistors.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The voltage generator subsystem is designed to perform multiple functions: it generates control voltages for both transistors, adapts to different input potential levels, and protects both transistors from damage. This multi-functional design reduces the need for separate dedicated circuits for each function, thereby reducing overall complexity.

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

Data Source

PatentEP3961923B1Device and method for level shift
Publication Date: 2026.03.04 STMICROELECTRONICS (GRENOBLE 2) SAS
  • EP3961923B1 patent drawingFigure 1
  • EP3961923B1 patent drawingFigure 2
  • EP3961923B1 patent drawingFigure 3

AI summary

This description relates to a method of supplying an output potential level from among two first levels as a function of an input level from among two second levels, comprising: supplying the output level by a first node (210) connecting together first (201) and second (202) transistors electrically in series between two second nodes (VGH, VGL) of application of the first levels; supplying, by a first voltage generator (230) supplied by one of the second nodes (VGH), a first DC voltage (V1) defining an upper limit of the control voltage of the first transistor; and supplying, by a second voltage generator (240) controlled by a value representative of the first voltage and supplied between the second nodes, a second DC voltage (V2) defining an upper limit of the control voltage of the second transistor.