ESD Protection Circuit With Zener-Capacitor Short-Circuit Withstand

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing electrostatic discharge protection devices are poorly suited to protect components biased at a few volts during nominal operation while also withstanding higher voltages during short circuits, leading to potential damage and reduced reliability.

Innovation Solution

The proposed devices incorporate specific configurations of diodes and capacitors, including Zener diodes and capacitive elements, to provide efficient electrostatic discharge protection while maintaining resistance to short circuits, with lower trigger voltages and dynamic resistances, allowing for efficient discharge and reduced voltage exposure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If existing electrostatic discharge protection devices are used, then electrostatic discharge protection is provided, but the device cannot withstand high voltages during short circuits

Engineering Contradiction:
Improveelectrostatic discharge protectionVSAvoidshort-circuit resistance
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The protection device is divided into multiple functional segments: a first protection branch with a first breakdown diode for electrostatic discharge protection, a second protection branch with a second breakdown diode and capacitor for high-voltage short circuit protection, and a third branch with a third breakdown diode. Each segment operates independently to address different protection needs, allowing the device to provide both electrostatic discharge protection and short-circuit resistance simultaneously.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The device employs dynamic switching between different protection paths based on the nature of the threat. During normal electrostatic discharge events, the first and third branches activate. During high-voltage short circuits, the second branch with the capacitor engages to handle the elevated voltage conditions. This dynamic adaptation allows optimal protection for different fault conditions.

Inventive Principle:
Principle #15Dynamics

2Strength

If existing protection devices are designed for high voltage short circuit withstand, then short-circuit resistance is improved, but electrostatic discharge protection capability deteriorates

Engineering Contradiction:
Improveshort-circuit resistanceVSAvoidelectrostatic discharge protection
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

Different parts of the protection device have specialized properties optimized for their specific function. The first breakdown diode and third breakdown diode are configured with lower breakdown voltages optimized for electrostatic discharge protection, while the second breakdown diode is paired with a capacitor to handle high-voltage short circuit conditions. This local optimization ensures each component performs its designated function effectively without compromising overall system performance.

Inventive Principle:
Principle #3Local quality

3Strength

If the breakdown voltage of protection diodes is increased to withstand short circuits, then short-circuit resistance is improved, but the trigger voltage for electrostatic discharge protection increases

Engineering Contradiction:
Improveshort-circuit resistanceVSAvoidtrigger voltage
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The protection function is segmented into multiple diodes with different breakdown voltage characteristics. The first and third breakdown diodes have lower breakdown voltages that provide early triggering for electrostatic discharge protection, while the second breakdown diode has higher breakdown voltage capability for short circuit withstand. This segmentation allows low trigger voltages for ESD protection while maintaining high short-circuit resistance.

Inventive Principle:
Principle #1Segmentation

4Reliability

If multiple protection branches are added to improve both electrostatic discharge protection and short-circuit resistance, then device complexity increases

Engineering Contradiction:
Improvecomprehensive protection capabilityVSAvoidnumber of components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Multiple protection functions are merged into a single integrated device structure. The first protection branch, second protection branch, and third branch are combined in parallel between the input terminal and reference terminal, creating a unified protection device that provides both electrostatic discharge protection and short-circuit resistance without requiring separate protection devices. This merging reduces overall system complexity while maintaining comprehensive protection capability.

Inventive Principle:
Principle #5Merging (Combining)

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 devices effectively dissipate electrostatic discharges with lower voltages, preventing damage to protected circuits and components, while maintaining protection against short circuits, thus enhancing the reliability of electronic devices.

Implementation Method 1

comprises a first protection branch including a first Zener diode, a second protection branch including a second Zener diode and a capacitor connected in series, and a third protection branch including a third Zener diode

Methodology Applied
Scientific EffectZener breakdown: Avalanche Breakdown

Implementation Method 2

a second protection branch including a second Zener diode and a capacitor connected in series

Methodology Applied
Scientific EffectCapacitance: Capacitance

Data Source

PatentEP4459677B1Electrostatic discharge protection device
Publication Date: 2026.03.11 STMICROELECTRONICS INT NV
  • EP4459677B1 patent drawingFigure 1~3
  • EP4459677B1 patent drawingFigure 4~6
  • EP4459677B1 patent drawingFigure 7~8

AI summary

This description relates to an electrostatic discharge protection device (300) comprising: - at least one first rectifier element (101) having an anode connected to a first terminal (109) and a cathode connected to a first node (111) of the device; - at least one second rectifier element (103) having an anode connected to a second node (113) of the device and a cathode connected to the first terminal (109); and - at least one Zener diode (301) or at least one Shockley diode connected in series with a capacitive element (303) between the first and second nodes (111, 113).