Slope-Controlled Electronic Switch for Low-EME Signal Transitions
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Solution Overview
Problem
Conventional switching techniques for binary signals with long transition times face challenges in minimizing electromagnetic emissions (EME) while avoiding feedback control and excessive switch partitions, leading to increased complexity and area consumption.
Innovation Solution
A low emission electronic switch design utilizing multiple current branches with slope circuitry, where each branch is sequentially activated or deactivated to follow a predetermined voltage-current function, reducing emissions without feedback and minimizing the number of switch partitions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional feedback control techniques are used to minimize electromagnetic emissions, then electromagnetic compatibility is improved, but circuit complexity and susceptibility to disturbances increase
Solution Approach 1:
The patent removes the feedback control mechanism from the switching circuit, extracting the harmful complexity and susceptibility to disturbances while maintaining the low emission characteristic through open-loop control with predetermined voltage-current functions
Solution Approach 2:
The switching circuit operates autonomously using predetermined voltage-current functions without requiring external feedback control, making the circuit self-sufficient and eliminating the need for complex feedback loops
2Object-affected harmful factors
If digitally-driven switches are partitioned into many smaller switches to reduce electromagnetic emissions, then electromagnetic compatibility is improved, but area consumption and circuit complexity increase excessively
Solution Approach 1:
The patent changes the control parameter from digital switching to analog voltage-current functions with predetermined slopes, allowing each switch to operate more efficiently and reducing the total number of switches needed while maintaining low emissions
Solution Approach 2:
The patent uses a manageable number of switches with controlled activation sequences rather than requiring thousands of partitions, applying partial action principles to achieve sufficient emission reduction without excessive circuit complexity
3Device complexity
If the number of switch partitions is reduced to decrease circuit complexity, then area consumption decreases, but electromagnetic emissions increase
Solution Approach 1:
The patent applies preliminary action by pre-defining voltage-current functions with specific slope characteristics before switching occurs, ensuring that even with fewer switches, the emission profile is controlled and minimized through predetermined activation sequences
Solution Approach 2:
The patent introduces dynamic control through adjustable slope circuitry that can modify the voltage-current characteristics in real-time, allowing each switch to contribute optimally to emission reduction while maintaining circuit simplicity
Data Source
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AI summary
A switch including multiple current branches and slope circuitry. The slope circuitry activates or deactivates the current branches one at a time according to a corresponding one of multiple slope functions in response to a transition of the input signal. Each current branch develops a current so that the output node follows a predetermined voltage-current function. Each slope function is other than a step function and may be linear or non-linear. A slope function may be configured as a current-starved inverter charging or discharging a capacitor with a fixed current. Delay circuitry may be included to delay the inputs or the outputs of the slope circuitry configured as multiple slope control circuits. The slope control circuits may be daisy-chained from first to last to effectuate the delay. Each current branch may include an electronic switch and may further include a resistor to determine the current level.