Adaptive DC Voltage Glitch Detection Circuit
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing circuits for detecting DC voltage glitches lack an adaptive detection threshold that varies proportionally with the voltage, making them ineffective in preventing circuit malfunctions, especially when the glitches are intentionally induced to access confidential data.
Innovation Solution
A detection circuit that incorporates a low-pass filter to generate a filtered voltage, which sets a detection threshold that varies proportionally with the DC voltage, using a combination of transistors and resistive elements with operational amplifiers to condition currents and voltages, allowing for adaptive glitch detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a fixed detection threshold is used for DC voltage glitch detection, then the circuit structure is simple, but the detection accuracy deteriorates when voltage levels vary
Solution Approach 1:
The patent applies the dynamics principle by transforming the fixed detection threshold into a dynamic threshold that automatically adapts to varying DC voltage levels. The threshold is made proportional to the instantaneous voltage through the use of transistors (Q1-Q4) and resistive elements that create a threshold voltage Vth = k*Vcc, where k is a proportionality constant. This dynamic adjustment ensures consistent glitch detection accuracy across different operating voltages without requiring complex external control circuits.
Solution Approach 2:
The patent implements parameter changes by modifying the detection threshold parameter from a fixed value to a variable that changes proportionally with the DC voltage. This is achieved through the transistor-resistor network where the threshold voltage parameter is derived from the supply voltage itself, allowing the detection system to maintain optimal sensitivity across varying voltage conditions while keeping the circuit structure relatively simple.
2Reliability
If the detection threshold varies proportionally to the DC voltage, then the glitch detection accuracy improves across varying voltage conditions, but the device complexity increases
Solution Approach 1:
The patent applies the self-service principle by designing a detection circuit that automatically adjusts its own threshold parameter based on the instantaneous DC voltage level. The transistor-resistor network (Q1-Q4 with associated resistors) forms a self-regulating threshold generation mechanism that requires no external control signals or additional sensing circuits. The circuit serves itself by using the supply voltage to generate the appropriate threshold, thereby improving reliability while minimizing added complexity.
3Adaptability or versatility
If a low-pass filter is used to generate the filtered voltage for threshold conditioning, then the adaptive detection capability is achieved, but the response time to detect glitches increases
Solution Approach 1:
The patent applies partial action by using a low-pass filter with a cutoff frequency that is partially attenuating but not excessively so. The filter constants (RC time constants in the transistor-resistor network) are chosen to provide sufficient smoothing for threshold stability while maintaining adequate response speed for glitch detection. This partial filtering approach achieves the necessary adaptability without overly sacrificing detection speed.
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 adapts the detection threshold to the DC voltage level, ensuring consistent glitch detection across varying voltage conditions, thereby enhancing the security and reliability of electronic circuits by preventing unauthorized access.
Implementation Method 1
a low-pass filter configured to supply said voltage obtained by filtering
Implementation Method 2
a first current varying proportionally to said voltage obtained by filtering conditions the detection threshold
Data Source
AI summary
A circuit for detecting a glitch in power supply includes a detection circuit to detect the glitch in a DC supply voltage of the power supply when a magnitude in the glitch in a DC supply voltage of the power supply exceeds a detection threshold, wherein the detection threshold is a function of the DC supply voltage, and wherein the detection circuit comprises a low pass filter, a control circuit coupled to the low pass filter, and a current mirror circuit coupled to the control circuit having an output for providing a logic signal indicative of a detected glitch.