Digital Signal Input Circuit With Comparator-Based Level Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing digital signal input circuits face precision issues in level conversion due to the low accuracy of light emitting diodes, leading to conversion errors when determining digital signal levels between integrated circuit chips.
Innovation Solution
A digital signal input circuit incorporating a voltage determining circuit with a voltage comparator that controls an isolating circuit to accurately determine and convert digital signal levels, replacing the use of light emitting diodes, and optionally including a resistive voltage division circuit and constant current source to expand the supported level range and ensure proper operation of the light emitting diode.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a light emitting diode is used to determine the level of a digital signal, then the circuit structure is simple, but the precision of determining the level is low and conversion errors easily occur
Solution Approach 1:
The patent replaces the light emitting diode-based level determination mechanism with a voltage comparator-based electronic system. The voltage comparator accurately compares the input signal voltage with a reference voltage to determine signal levels, eliminating the precision limitations of light emitting diodes while maintaining circuit simplicity through integrated electronic components.
Solution Approach 2:
The patent changes the operating parameters by using a voltage comparator that operates in its linear region to provide accurate voltage comparison, rather than relying on the non-linear characteristics of light emitting diodes. This parameter change enables precise level determination across a wider voltage range.
2Ease of manufacture
If a light emitting diode is used to determine the level of a digital signal, then the circuit is easy to implement, but the range of supported digital signal levels is limited
Solution Approach 1:
The voltage comparator is designed to handle multiple voltage levels and signal types by adjusting the reference voltage. This universal approach allows the same circuit to accurately determine different digital signal levels (e.g., 5V, 3.3V, 1.8V logic levels) without requiring different circuit topologies, thereby expanding adaptability while maintaining ease of implementation.
3Adaptability or versatility
If voltage division is performed using resistors before input to the isolating circuit, then the circuit can interface with different voltage levels, but the precision of level determination deteriorates due to the light emitting diode's limitations
Solution Approach 1:
The voltage comparator acts as an intermediary between the voltage division circuit and the isolating circuit. It receives the divided voltage signal and accurately determines the original signal level by comparing it with an appropriate reference voltage, thereby restoring precision that would otherwise be lost in the voltage division process.
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 enhances the accuracy and range of digital signal level conversion, reducing conversion errors and ensuring compatibility with a wider range of digital signal levels supported by target chips, thereby improving the correctness and adaptability of digital signal input circuits.
Implementation Method 1
a voltage comparator, a first input end of the voltage comparator is connected to the input end of the digital signal, a second input end of the voltage comparator is connected to a reference voltage source, and an output end of the voltage comparator is connected to a switching device, where the voltage comparator is configured to control an on/off state of the switching device according to a high-low relationship between the level of the digital signal and a level of the reference voltage source
Implementation Method 2
A light emitting diode 120 in the isolating circuit determines whether a level of the digital signal is a high level or a low level
Data Source
AI summary
A digital signal input circuit including an isolating circuit and a voltage determining circuit is presented, where a first port of an input end of the isolating circuit receives a digital signal, an output end of the isolating circuit outputs the digital signal, and when the isolating circuit is open, the isolating circuit is configured to output a first level, or when the isolating circuit is closed, the isolating circuit is configured to output a second level; and the voltage determining circuit is configured to determine, according to a level of the digital signal, whether the isolating circuit is open or closed. According to the digital signal input circuit, the voltage determining circuit determines a level of a digital signal, thereby correctness of digital signal level conversion is increased.