RF Switch Circuit Grouped Control for Uniform ESD Dissipation
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Solution Overview
Problem
Existing radio frequency switch circuits face challenges in dissipating electrostatic discharge (ESD) effectively due to voltage transient changes, leading to different switching operations among transistors and reduced ESD dissipation capability.
Innovation Solution
The proposed radio frequency switch circuit includes a series circuit with two series connection groups, where the control terminals of the first series connection group are coupled to a first control node and those of the second series connection group are coupled to a second control node. During an ESD event, the voltages at these control nodes differ, resulting in relatively close switching voltages for the transistors in both groups, allowing them to perform uniform switching operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If transistors are connected in series with common control terminal, then the circuit can be controlled uniformly, but the switching voltages of transistors become different during ESD events
Solution Approach 1:
The patent divides the series connection of transistors into multiple groups, where each group has its own control terminal. This segmentation allows different control voltages to be applied to different groups, enabling uniform switching response during ESD events while maintaining controlled operation during normal use.
Solution Approach 2:
The patent applies different control voltages to different groups of transistors based on their local requirements during ESD events. By making the control voltage local rather than common, each transistor group can respond uniformly to ESD stress while maintaining overall circuit control.
2Strength
If the number of transistors in series increases, then the voltage handling capability increases, but the difference in switching voltages among transistors increases
Solution Approach 1:
The patent segments the series-connected transistors into multiple groups with separate control terminals. This allows the circuit to handle higher voltages through series connection while maintaining uniform switching response within each group by applying appropriate control voltages to each group's control terminal.
Solution Approach 2:
The patent changes the control voltage parameter applied to different groups of transistors to compensate for the voltage division effects in series connections. By adjusting the control voltage for each group, the switching characteristics are equalized across all transistors regardless of their position in the series chain.
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
This design enhances the capability of dissipating ESD by ensuring that all transistors in the switch circuit respond uniformly to ESD events, thereby improving the circuit's overall ESD dissipation performance.
Implementation Method 1
the ESD voltage VESD may be coupled to the control terminals of the transistors T1 to T8 through the parasitic capacitance of the transistor T1
Data Source
AI summary
A radio frequency switch circuit includes a series circuit. The series circuit includes a first series connection group and a second series connection group. The first series connection group includes a plurality of first transistors. The second series connection group includes a plurality of second transistors. Control terminals of the first transistors are all coupled to a first control node. Control terminals of the second transistors are all coupled to a second control node. When an electrostatic discharge event occurs, a voltage at the first control node is different from a voltage at the second control node. In a normal operation state, a switch state of the first series connection group and a switch state of the second series connection group are the same as each other.