Pass Switch Impedance Tuning for Lower Jitter and Attenuation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Electronic switches introduce jitter or reduce the amplitude of analog signals due to their impedance transfer function, particularly affecting high-frequency components in broadband communications.
Innovation Solution
A pass switch circuit with an impedance circuit communicatively coupled to a pass transistor, where the impedance is sized to minimize attenuation by lowering the corner frequency, and additional activation signals are used to speed up the transistor's turn-on time, ensuring uniform impedance for all data signals and reducing jitter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a pass switch is used to transmit analog signals, then signal routing control is achieved, but jitter is introduced to the signal
Solution Approach 1:
An impedance circuit is introduced as an intermediary component between the signal source and the pass transistor. This impedance circuit compensates for the non-ideal impedance characteristics of the pass transistor, thereby reducing signal jitter while maintaining routing control functionality
Solution Approach 2:
The impedance of the impedance circuit is specifically designed and adjusted to counteract the frequency-dependent impedance variations of the pass transistor. By changing the impedance parameters of the circuit, the overall transfer function is optimized to minimize jitter in the transmitted signal
2Ease of operation
If a pass switch is used to transmit analog signals, then signal routing control is achieved, but signal amplitude is reduced
Solution Approach 1:
The impedance circuit serves as a mediator that compensates for amplitude loss by counteracting the attenuation effects of the pass transistor's impedance transfer function, thereby maintaining signal amplitude while preserving routing control
Solution Approach 2:
The impedance circuit parameters are optimized to compensate for signal attenuation across the frequency spectrum, ensuring that the overall system maintains adequate signal amplitude while achieving effective signal routing
3Loss of energy
If impedance circuit is added to minimize attenuation, then signal amplitude is maintained, but device complexity increases
Solution Approach 1:
A relatively simple impedance circuit is introduced as an intermediary to counteract the complex impedance effects of the pass transistor, achieving amplitude maintenance without requiring overly complex circuitry
Solution Approach 2:
By adjusting the impedance parameters of a simple circuit configuration, the patent achieves effective compensation for signal attenuation without introducing excessive circuit complexity, balancing performance and simplicity
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 minimizes signal jitter and attenuation, ensuring that all data signals experience the same level of attenuation, thereby reducing jitter from 11.3 picoseconds to 4.36 picoseconds, and allows for high-speed data transmission.
Implementation Method 1
An impedance transfer function of the pass switch circuit is determined at least in part by an impedance of the impedance circuit, and the impedance of the impedance circuit is sized to minimize attenuation of the electronic signal due to the impedance transfer function of the pass switch circuit
Data Source
AI summary
A system includes a pass switch circuit and a first pass switch activation circuit. The pass switch circuit includes an impedance circuit and a pass transistor having a first source/drain connection, a second source/drain connection, and a gate input. The pass switch circuit passes an electronic signal from the first source/drain connection to the second source/drain connection in response to activation of the gate input. An impedance transfer function of the pass switch circuit is determined at least in part by an impedance of the impedance circuit and the impedance is sized to minimize attenuation of the electronic signal due to the impedance transfer function of the pass switch circuit. The first pass switch activation circuit provides a first activation signal to the gate input in response to an enable signal.