Comparator-Based Optocoupler Circuit for Fast Isolation Switching
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Solution Overview
Problem
Existing optocouplers face challenges in high-speed communication due to significant delays associated with turning ON and OFF, particularly at high communication speeds above 10-20 kilo-Baud, and are costly when used in multiple isolation devices, especially in low-voltage and low-current circuits.
Innovation Solution
The implementation of high-speed optocoupler circuits with minimal components and quick turn ON and OFF transitions, utilizing a comparator and optocoupler configurations with two non-ground operating levels, a Zener diode, and a feedback loop to minimize delays and optimize performance across different phototransistor gains.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If traditional optocoupler configurations are used, then isolation between circuits is achieved, but significant turn-ON and turn-OFF delays occur at high communication speeds
Solution Approach 1:
The patent implements dynamic operation by using a comparator circuit that rapidly switches between two voltage levels based on the input signal state. This dynamic switching mechanism enables the optocoupler to respond quickly to signal changes, achieving high communication speeds while minimizing turn-ON and turn-OFF delays through active level transitions rather than passive response
Solution Approach 2:
The patent changes the operating parameters by utilizing two non-ground voltage levels instead of traditional ground-referenced operation. This parameter change allows the circuit to operate in a high-speed regime where the comparator can rapidly detect and respond to voltage level changes, significantly reducing transition delays and enabling communication speeds above 10-20 kilo-Baud
2Reliability
If multiple isolation devices are used to achieve reliable isolation, then circuit isolation is improved, but system cost increases significantly
Solution Approach 1:
The patent creates a universal optocoupler circuit design that provides reliable isolation while maintaining cost-effectiveness through a standardized comparator-based architecture. This multi-functional circuit simultaneously achieves circuit isolation, high-speed operation, and cost efficiency, eliminating the need for multiple separate isolation devices and reducing overall system cost while maintaining reliability
Solution Approach 2:
The patent employs inexpensive comparator circuits and standard optocoupler components to create a cost-effective isolation solution. By using affordable, readily available components in a clever configuration, the patent achieves reliable isolation without requiring expensive specialized devices, making the solution economically viable for multiple device applications
3Use of energy by moving object
If optocouplers are used in low-voltage and low-current circuits, then power consumption is reduced, but the optocoupler performance and speed are degraded
Solution Approach 1:
The patent changes the voltage level parameters by implementing two non-ground operating levels, allowing the optocoupler to operate effectively in low-voltage environments. This parameter change enables the comparator to detect and respond to small voltage changes with high speed, maintaining fast response performance even when operating with reduced voltage and current levels
Solution Approach 2:
The patent replaces traditional passive optocoupler response mechanisms with an active comparator-based detection system. This substitution enables the circuit to achieve high-speed operation at low power levels by using active voltage level detection and switching, overcoming the typical speed limitations associated with low-voltage operation
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
These configurations enable reliable high-speed communication at rates such as 230 kilo-Baud by reducing turn-ON and turn-OFF delays and maintaining compatibility with low-voltage environments, while being cost-effective for multiple device applications.
Implementation Method 1
An optocoupler typically includes a light source (e.g., a light emitting diode (LED))
Implementation Method 2
the phototransistor detects an illumination level of the light source
Data Source
AI summary
An optocoupler circuit includes first and second resistors, an optocoupler, a reference circuit, and a comparator. The optocoupler includes a light source and a phototransistor. The light source is connected to form a first voltage divider with the first resistor. The phototransistor is connected to form a second voltage divider with the second resistor. The optocoupler transitions an output of the second voltage divider between first and second levels. Magnitudes of the first and second levels are greater than zero. The reference circuit is configured to output a reference voltage. The comparator includes a first input and a second input. The first input receives an output of the first voltage divider. The second input receives the reference voltage. An output of the comparator transitions between a third level and a fourth level based on a comparison between the output of the first voltage divider and the reference voltage.