Supply Oscillation Detection Circuit Using Filtered Peak Sensing
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Solution Overview
Problem
Existing detection circuits for oscillations in regulated supply signals, particularly at high frequencies, are ineffective due to limited bandwidth and require fast comparators, making them unsuitable for detecting instability in voltage regulators.
Innovation Solution
A detection circuit that includes a filter circuit to isolate high-frequency oscillations, a peak value detector circuit to identify extreme values, and a comparator circuit to compare these values with threshold signals, allowing for the detection of oscillations without the need for fast comparators, with adjustable bandwidth and threshold settings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If voltage detectors with comparators are used to detect oscillations, then oscillation detection is achieved, but detection effectiveness at high frequencies (>10 MHz) is insufficient
Solution Approach 1:
The detection circuit is segmented into three functional blocks: a filter circuit (high-pass or bandpass) to isolate oscillation frequencies, a peak value detector circuit to capture extreme values, and a comparator circuit to evaluate threshold conditions. This segmentation allows each block to be optimized for its specific function, enabling effective high-frequency oscillation detection without requiring the entire circuit to operate at maximum speed simultaneously.
Solution Approach 2:
The peak value detector circuit acts as an intermediary between the filter circuit and the comparator circuit. It captures and holds the extreme values of the filtered signal, allowing the comparator to evaluate these values at its own pace without being constrained by the high-frequency oscillation rate. This intermediary function enables reliable detection of high-frequency oscillations while using standard-speed comparators.
2Adaptability or versatility
If fast comparators are used to detect high-frequency oscillations, then detection bandwidth is improved, but device complexity and cost increase
Solution Approach 1:
The detection circuit is segmented into three functional blocks: a filter circuit (high-pass or bandpass) to isolate oscillation frequencies, a peak value detector circuit to capture extreme values, and a comparator circuit to evaluate threshold conditions. This segmentation allows each block to be optimized for its specific function, enabling effective high-frequency oscillation detection without requiring the entire circuit to operate at maximum speed simultaneously.
Solution Approach 2:
The filter circuit performs preliminary action by pre-processing the supply signal to isolate and amplify the oscillation components before they reach the peak value detector and comparator. This preliminary filtering removes DC components and low-frequency variations, allowing the subsequent stages to focus solely on detecting high-frequency oscillations, thereby extending the effective detection bandwidth without requiring ultra-fast comparators.
3Measurement precision
If high-pass or bandpass filter circuits are used to filter DC components, then oscillation detection accuracy is improved, but lower limit frequency detection capability is reduced
Solution Approach 1:
The filter circuit parameters (cutoff frequencies, Q-factor) can be dynamically adjusted based on the expected oscillation frequency range. For detecting lower frequency oscillations, the high-pass filter's cutoff frequency can be lowered, while for high-frequency detection, the bandpass filter can be tuned to the appropriate range. This dynamic adaptability allows the same detection circuit architecture to maintain high detection accuracy across a broad frequency spectrum from low to high frequencies.
Solution Approach 2:
The detection circuit is designed with universal filter circuit options (both high-pass and bandpass configurations) that can handle different frequency ranges. The peak value detector and comparator circuits are also designed to work with various filter outputs, making the entire system multi-functional. This universality allows the circuit to detect oscillations across a wide frequency range while maintaining detection accuracy through appropriate filter selection for each application.
Data Source
AI summary
The present disclosure relates to a detection circuit for detecting oscillations of a regulated supply signal. The detection circuit includes a filter circuit to filter the regulated supply signal in order to obtain a filtered supply signal. A peak value detector circuit is designed to detect an extremum of the filtered supply signal. A comparator circuit is designed to compare the detected extreme value with a threshold value and to indicate an understepping or exceedance of the threshold value.