Microwave Gate Control Circuit for Fast Switching Without Crosstalk
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Solution Overview
Problem
Existing power semiconductor device control methods face limitations in setting dead time of control signals at high frequencies, leading to low efficiency and crosstalk in circuits, and position constraints of control units cause mistaken turn-on of switch transistors.
Innovation Solution
A control circuit using a microwave unit to convert control signals into microwave signals for transmission, allowing for short dead times without crosstalk by enabling long distances between transmitting and receiving terminals, thus preventing mistaken turn-on of switch transistors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the dead time of control signal is shortened to improve switching efficiency at high frequencies, then productivity is improved, but crosstalk in the circuit occurs leading to reliability degradation
Solution Approach 1:
The patent introduces an isolation unit as an intermediary component between the control signal transmission path and the switch transistor. This isolation unit acts as a mediator that blocks the harmful crosstalk while allowing the control signal to pass through, thereby enabling short dead times without causing crosstalk-induced reliability issues.
Solution Approach 2:
The patent extracts and removes the parasitic capacitance that causes crosstalk from the control circuit path. By taking out this harmful element through the isolation unit, the system can operate with shortened dead times at high frequencies without suffering from crosstalk effects.
2Speed
If the control unit is positioned close to the switch transistor to reduce signal transmission distance, then response speed is improved, but crosstalk and mistaken turn-on occur due to parasitic capacitance
Solution Approach 1:
The isolation unit serves as an intermediary that allows the control unit to be positioned optimally without directly causing crosstalk. It mediates between the control signal and the switch transistor, enabling fast response while preventing mistaken turn-on through its isolation function.
Solution Approach 2:
The patent replaces the direct electrical connection (mechanical/electrical coupling) between the control unit and switch transistor with an isolation-based approach. This substitution eliminates the parasitic capacitance coupling that causes mistaken turn-on while maintaining signal transmission capability.
3Reliability
If transformer or optocoupler control is used to isolate control signals, then crosstalk is reduced, but device complexity and signal transmission limitations occur
Solution Approach 1:
The patent changes the electrical parameters of the control path by introducing the isolation unit, which modifies the impedance and coupling characteristics. This parameter change enables effective crosstalk isolation without requiring complex transformer or optocoupler-based isolation circuits.
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
Improves efficiency and prevents crosstalk by allowing quick switching of transistors at high frequencies with minimal interference, even at long distances, using microwave units to isolate parasitic capacitance.
Implementation Method 1
the transmitting terminal of the microwave unit can convert the control signal into the microwave signal and transmit the microwave signal to the receiving terminal of the microwave unit
Implementation Method 2
since the microwaves can be transmitted without depending upon any medium, a distance between the transmitting terminal and the receiving terminal of the microwave unit can be relatively long
Data Source
Figure 1~2
Figure 3a~3b
Figure 4a~4b
AI summary
Provided are a control circuit and a control method for a switch transistor. The control circuit includes: a control unit (210) configured to output a control signal; and a microwave unit (220) having a transmitting terminal connected to the control unit (210) and a receiving terminal connected to at least one switch transistor (230). The transmitting terminal is configured to receive the control signal and convert the control signal into a microwave signal. The receiving terminal is configured to convert the microwave signal into the control signal to control turn-on or turn-off of the at least one switch transistor (230). The control circuit may turn on or turn off the switch transistor quickly without causing crosstalk in the circuit, even if dead time of the control signal is short. In addition, since transmission of microwaves does not rely on any medium, a distance between the transmitting terminal and the receiving terminal of the microwave unit can be relatively long, thereby avoiding the crosstalk in the circuit, and preventing the switch transistor from being wrongly turned on.