High-Voltage Level Shifter Feedback Against Noise-Induced Switching

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional level shifter circuits face issues such as slow transition due to parasitic capacitances, high static consumption, low immunity to noisy environments, and potential data loss, particularly in applications involving high-voltage and high-current systems like ultrasound pulsers.

Innovation Solution

A high-voltage level shifter circuit with a feedback function, utilizing capacitive feedback and a logic control system to ensure consistency between input and output signals, which includes a capacitor to shift voltage levels and a logic control element sensitive to output signals for refreshing data, thereby preventing data loss and reducing static consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If conventional level shifter circuits are used, then voltage level translation is achieved, but transition speed is slow due to parasitic capacitances

Engineering Contradiction:
Improvetransition speedVSAvoidparasitic capacitances
Core Design Contradiction:
SpeedVSObject-generated harmful factors

Solution Approach 1:

The patent extracts and removes the problematic parasitic capacitances from the circuit by replacing conventional MOS-based level shifting elements with a transmission gate-based architecture that minimizes parasitic effects, thereby achieving faster transition speeds

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the electrical parameters of the level shifter by using transmission gates with optimized on-resistance and minimal parasitic capacitance, transforming the circuit's switching characteristics to achieve faster transitions while maintaining voltage level translation functionality

Inventive Principle:
Principle #35Parameter changes

2Use of energy by moving object

If conventional level shifter circuits are used, then voltage level translation is achieved, but static consumption is high

Engineering Contradiction:
Improvestatic consumptionVSAvoiddata loss immunity
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent implements a refresh mechanism that periodically updates the stored voltage level information in the capacitor-based memory element, ensuring data integrity without continuous power consumption, thus achieving low static consumption while maintaining reliability

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent employs a feedback mechanism that monitors the output voltage level and triggers refresh operations only when necessary, minimizing unnecessary power consumption while ensuring data consistency and preventing loss in the capacitor-based storage element

Inventive Principle:
Principle #23Feedback

3Reliability

If conventional level shifter circuits are used, then voltage level translation is achieved, but immunity to noisy environments is low

Engineering Contradiction:
Improvenoise immunityVSAvoidnoisy power supplies and environments
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent uses a capacitor-based memory element that stores voltage level information with inherent noise immunity, and implements a refresh mechanism that corrects potential errors before they propagate, providing beforehand protection against noisy environments

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The patent implements a feedback mechanism that continuously monitors the output voltage level and compares it with the stored reference information, triggering corrective refresh operations when noise-induced deviations are detected, thereby maintaining high noise immunity

Inventive Principle:
Principle #23Feedback

4Reliability

If conventional level shifter circuits are used, then voltage level translation is achieved, but robustness to data loss is reduced

Engineering Contradiction:
Improverobustness to data lossVSAvoiddata loss
Core Design Contradiction:
ReliabilityVSLoss of information

Solution Approach 1:

The patent employs a capacitor-based memory element that stores voltage level information with inherent redundancy, and implements a refresh mechanism that proactively corrects potential data loss before it occurs, providing beforehand protection against destructive events

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The patent implements a feedback mechanism that monitors the integrity of stored voltage level information and triggers refresh operations when degradation or data loss is detected, ensuring continuous robustness against data loss and preventing destructive events

Inventive Principle:
Principle #23Feedback

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

The solution provides high immunity to noisy power supplies and environments, enables fast transitions, and minimizes static consumption, effectively preventing data loss and ensuring reliable operation in noisy conditions.

Implementation Method 1

a feedback element (e.g. 10) coupled to said output stage for transferring to said input stage a feedback signal (e.g. 20) representative of the output level (e.g. Q_N) of the output stage, wherein the input stage includes control circuitry (e.g. 12 to 18, 22), said control circuitry sensitive to said input signal and said feedback signal

Methodology Applied
Scientific EffectCapacitive feedback: Capacitance

Data Source

PatentEP3174203B1A level shifter circuit, corresponding apparatus and method
Publication Date: 2019.12.25 STMICROELECTRONICS SRL
  • EP3174203B1 patent drawingFigure 1
  • EP3174203B1 patent drawingFigure 2
  • EP3174203B1 patent drawingFigure 3

AI summary

In an embodiment, a level shifter circuit for driving a load (HSP) via a power supply line (HVP) includes: - an input stage (CL) for receiving an input signal (IN) switchable between a first and a second input level (0, LVP), - an output stage (LL, A) coupled to the power supply line (HVP) to produce a drive signal (G) for the load (HSP), the output stage (LL, A) switchable between a first and a second output level (REF_HVP, HVP), - a level translator (LT) set between the input stage (CL) and the output stage (LL, A), whereby the input signal (IN) switching between the first and second input levels (0, LVP) translates into the output stage (LL, A) switching between the first and second output levels (REF_HVP, HVP)- A feedback element (10) is provided coupled to the output stage (LL, A) for transferring to the input stage (CL) a feedback signal (20) representative of the output level of the output stage (LL, A); the input stage (CL) includes control circuitry (12 to 18, 22) sensitive to the input signal (IN) and the feedback signal (Q_N) for detecting undesired switching of the output stage (LL, A) between the first and second output levels (REF_HVP, HVP) occurring in the absence of input signal (IN) switching between the first and second input levels (0, LVP), the control circuitry (12 to 22) being configured (22) for inverting the output level (Q_N) of the output stage (LL, A) resulting from undesired switching.