Parasitic Peak Detector Circuit Using Transistor RC Threshold
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Solution Overview
Problem
Existing detectors for power supply disturbances, such as parasitic peaks, are ineffective in detecting short-duration peaks and are complex in structure, making them unsuitable for modern electronic circuits vulnerable to fault injection attacks.
Innovation Solution
A detector circuit utilizing transistors with carefully chosen resistive and capacitive elements to directly compare unfiltered supply voltage with a self-adaptive threshold, enabling detection of both positive and negative parasitic peaks of short duration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional voltage comparator-based detectors are used, then detection of power supply disturbances is provided, but the detector cannot detect short-duration parasitic peaks and has complex structure
Solution Approach 1:
The patent extracts only the essential detection function from the complex voltage comparator structure, using a single transistor to detect parasitic peaks. This removes unnecessary filtering and comparison circuitry while retaining the core detection capability, achieving both simplicity and effectiveness in detecting short-duration disturbances
Solution Approach 2:
Instead of filtering the supply voltage before detection as in conventional comparators, the patent inverts the approach by directly detecting unfiltered voltage variations with a transistor. The transistor's base receives the raw supply voltage, allowing direct detection of fast transient peaks without the lag introduced by filtering circuits
2Object-affected harmful factors
If filtering circuits are added to the detector, then noise reduction is achieved, but the detector cannot respond to short-duration parasitic peaks
Solution Approach 1:
The patent applies local quality by using a capacitor connected to the transistor's emitter that provides localized filtering only for the threshold reference voltage, while the main supply voltage detection path remains unfiltered. This selective filtering approach reduces noise in the reference signal without slowing down the response to actual parasitic peaks in the supply voltage
3Reliability
If voltage comparator-based detection is implemented, then disturbance detection is provided, but the solution is not compact for integrated circuits
Solution Approach 1:
The patent extracts the detection function to a single transistor plus a capacitor and resistor, eliminating the need for complex comparator circuits, multiple filtering stages, and associated support circuitry. This minimal component set dramatically reduces the area required for implementation in integrated circuits while maintaining reliable disturbance detection
Solution Approach 2:
The patent merges the detection function with the existing power supply network by using the supply voltage directly at the transistor base and utilizing standard RC time constant formation. This integration approach eliminates separate detection circuit blocks and reduces overall circuit footprint
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 effectively detects short-duration parasitic peaks, providing a simple and compact solution that is compatible with modern electronic circuits, enhancing security against fault injection attacks by quickly identifying and responding to potential disturbances.
Implementation Method 1
a first transistor whose control terminal is connected to a terminal for application of a first potential of a supply voltage of the circuit and of which a first conduction terminal is connected to a terminal for application of a second potential via at least one first resistive element
Implementation Method 2
a first capacitive element connects said first conduction terminal to a terminal for applying a reference potential of the supply voltage, the respective values of the first resistive element and of the first element capacitive being chosen according to the minimum duration of the parasitic peaks to be detected
Data Source
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AI summary
The circuit has a transistor (MP51) whose control terminal is connected to a positive terminal (52) for application of a supply voltage (Vcc). The transistor has a conduction terminal connected to the terminal (52) through a resistive element (R1) and to a ground terminal (53) through a capacitive element (C). The transistor has another conduction terminal providing a result voltage (Vd) representing the detection of parasite spike. The values of the resistive and capacitive elements are chosen based on minimum duration of parasite spike to be detected.