Surge Protection Circuit with Distributed Semiconductor Switches

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Solution Overview

Problem

Mains-driven electrical loads, such as LED circuits, face challenges with power transients that exceed the voltage limits of typical silicon-based integrated circuits, leading to potential damage from surges, and existing surge protection solutions are bulky and costly.

Innovation Solution

A surge protection circuit utilizing a plurality of switches connected in series across multiple semiconductor dies, with surge detection means and switch drivers to distribute the surge voltage, reducing the risk of damage and incorporating clamping diodes and communication means for efficient detection and distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional surge protection circuits using energy absorbers such as varistors or capacitors are employed, then surge protection is provided, but the circuits become bulky and require additional components

Engineering Contradiction:
Improvesurge protection capabilityVSAvoidcircuit component count
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention segments the surge protection function across multiple semiconductor dies, with each die containing a switch and surge detection means. This distributes the protection capability without requiring external energy absorbers or additional discrete components, resolving the contradiction between reliability and device complexity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The semiconductor dies perform dual functions: normal circuit operation and surge detection/response. The same switches used for circuit control also serve to distribute surge voltage, eliminating the need for separate protection components and reducing overall circuit complexity while maintaining protection capability

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

2Device complexity

If a single semiconductor die is used for mains voltage switching, then circuit simplicity is maintained, but the die is susceptible to irreparable high voltage damage from surges

Engineering Contradiction:
Improvecircuit structureVSAvoidsurge resistance
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The invention divides the voltage blocking function across multiple semiconductor dies connected in series. Each die only needs to withstand a fraction of the total surge voltage, making them individually resistant to damage while collectively providing comprehensive protection. This segmentation approach maintains circuit simplicity while dramatically improving surge resistance

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The series-connected switches are positioned to open before the surge voltage can damage the semiconductor dies. The surge detection means triggers the switches to open in advance, cushioning the dies from the full brunt of the surge voltage and preventing irreparable damage while maintaining structural simplicity

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

Data Source

PatentEP2327275B1A surge protection circuit having serially connected series switches
Publication Date: 2016.02.10 NXP BV
  • EP2327275B1 patent drawingFigure 1~2
  • EP2327275B1 patent drawingFigure 3
  • EP2327275B1 patent drawingFigure 4

AI summary

A surge protection circuit is disclosed for an electrical Load which may be for instance an LED load which is directly connected to a supply such as mains supply, and comprises a plurality of switches which are distributed across a plurality of semiconductor die. A surge detector detects the start of a spike in the supply, which results from, for example the commencement or interruption of a nearby inductive load, and opens all the switches. By distributing the switches across multiple die the peak voltage across each is reduced relative to using a single die; thereby each die can stay within the absolute maximum voltage capacity. Each die may have its own surge detector; alternatively, a single surge detector may be used which communicates with the switches on each of the die. In an extension the bridge rectifier may be integrated into the circuit distributed across the die. In this embodiment additional inter-die clamping diodes are required to prevent unsafe floating of the edge connections of each die.