EMI Sensor Circuit for Semiconductor Tamper Detection

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Solution Overview

Problem

Existing semiconductor devices lack effective mechanisms to prevent and detect electromagnetic interference (EMI) attacks and physical tampering, compromising security in electronic systems.

Innovation Solution

Incorporation of EMI sensors, including E and H field sensors, with a sensing circuit to monitor voltage fluctuations and generate a failsafe response upon detection of EMI attacks or physical tampering, utilizing hysteresis comparators and voltage level comparators to differentiate between legitimate signals and malicious interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If EMI sensors and sensing circuits are added to detect EMI attacks and physical tampering, then security and detection capability are improved, but device complexity increases

Engineering Contradiction:
ImprovesecurityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The sensing circuit is divided into separate functional blocks: E field sensor, H field sensor, hysteresis comparator, and voltage level comparator. Each sensor type independently detects specific aspects of EMI or tampering, allowing the system to monitor multiple threat vectors simultaneously while maintaining modular architecture that manages complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The sensing circuit serves multiple security functions: detecting EMI attacks through E and H field sensors, detecting physical tampering through voltage level comparators, and providing failsafe responses. This multi-functionality consolidates what would otherwise require separate systems into a single integrated security module.

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

2Measurement precision

If hysteresis comparators and voltage level comparators are used to differentiate between legitimate signals and malicious interference, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improvedetection precisionVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The hysteresis comparator implements feedback through its inherent hysteresis characteristic, where the comparator threshold depends on the previous output state. This feedback mechanism creates distinct upper and lower thresholds that prevent false triggering on noise edges, enabling precise differentiation between legitimate signal transitions and malicious EMI interference.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The sensing circuit utilizes parameter changes in voltage levels to detect different types of threats. The voltage level comparator monitors for specific voltage thresholds indicating physical tampering, while the hysteresis comparator detects EMI-induced voltage fluctuations. By monitoring multiple voltage parameters simultaneously, the system achieves high detection precision.

Inventive Principle:
Principle #35Parameter changes

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 detects and responds to EMI attacks and physical tampering, ensuring the security of secure data by placing the system into a safe state to prevent hacking.

Implementation Method 1

an electric (E) field sensor and a magnetic (H) field sensor to avoid EMI attacks

Methodology Applied
Scientific EffectElectric field: Electric Field

Implementation Method 2

an electric (E) field sensor and a magnetic (H) field sensor to avoid EMI attacks

Methodology Applied
Scientific EffectMagnetic field: Magnetic Field

Implementation Method 3

The sensing circuit includes a hysteresis comparator having a first input coupled to a first node of the EMI sensor via a low pass filter

Methodology Applied
Scientific EffectHysteresis: Hysteresis

Data Source

PatentEP4509845B1Semiconductor device having electromagnetic interference (EMI) sensors and a sensing circuit to detect EMI attacks
Publication Date: 2026.03.11 NXP BV
  • EP4509845B1 patent drawingFigure 1
  • EP4509845B1 patent drawingFigure 2

AI summary

A semiconductor device includes a secured circuit, an electromagnetic interference (EMI) sensor over a surface of the secured circuit, and a sensing circuit. The EMI sensor is configured to receive a reference voltage and the EMI sensor includes at least one of electric (E) field sensor or a magnetic (H) field sensor. The sensing circuit includes a hysteresis comparator and a voltage level comparator. The hysteresis comparator has a first input coupled to a first node of the EMI sensor via a low pass filter, a second input directly connected to the first node, and an output configured to provide an output indicative an EMI attack. An antenna portion of the EMI sensor includes the first node and is coupled between inputs of the voltage level comparator, in which the voltage comparator is configured to provide an output indicative of a physical tampering with the antenna portion.