Bidirectional MOS Switch Gate Drive for Low-Current Turn-On
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Solution Overview
Problem
Existing high-voltage bidirectional switch devices face challenges with high current consumption during turn-on due to parasitic capacitance discharge, complex and costly circuit design, and variable turn-on currents, which affect efficiency and area occupation in charge recovery resonant drivers.
Innovation Solution
A high-voltage bidirectional switch device with a control and driving stage that uses a driving transistor and switching transistor in inverter configuration, driven by specific signals to manage turn-on and turn-off, minimizing parasitic capacitance discharge and optimizing current usage, and avoiding connection to ground during turn-off.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional current generators are used to charge parasitic capacitance during turn-on, then switching speed is improved, but current consumption becomes excessively high and circuit complexity increases
Solution Approach 1:
The parasitic capacitance of the bidirectional switch is charged by the current naturally flowing during the turn-on transition itself, rather than by a dedicated current generator. The current that flows during the switching transition is reused to charge the capacitance, eliminating the need for separate high-current generation circuits and reducing overall current consumption while maintaining fast switching speeds
2Ease of operation
If dedicated current generators are added to manage turn-on current, then switching control is improved, but device complexity and area occupation increase
Solution Approach 1:
The dedicated current generator component is extracted and removed from the circuit. Instead of adding complex current generation circuitry, the invention uses the existing current flow during switching transitions to charge the parasitic capacitance, simplifying the overall circuit design while maintaining effective switching control through the natural dynamics of the circuit elements
3Reliability
If parasitic capacitance is fully discharged during turn-off, then switching completeness is improved, but energy loss increases due to repeated recharging
Solution Approach 1:
Instead of completely discharging the parasitic capacitance to ground during turn-off (which wastes energy), the invention allows the capacitance to retain its charge. The charged capacitance is then recovered and reused during the next turn-on transition, eliminating the need for repeated full charging cycles and reducing energy loss while maintaining reliable switching 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
This solution reduces current consumption, simplifies circuit design, and minimizes area occupation while maintaining fast turn-on and turn-off times, improving overall efficiency and reducing power consumption in charge recovery resonant drivers.
Implementation Method 1
a driving transistor connected to a supply terminal and driven by a first driving signal to charge an internal gate node and turn on the bidirectional switch
Implementation Method 2
a switching transistor driven by a second driving signal to short-circuit the internal gate and source nodes and turn off the bidirectional switch
Implementation Method 3
a voltage limiting element connected between the internal gate and source nodes
Data Source
AI summary
A switch device is described, formed by: a first switch MOS transistor, with its drain terminal connected to a first switch terminal, source terminal connected to an internal source node and gate terminal connected to an internal gate node; a second switch MOS transistor, with its drain terminal connected to a second switch terminal, source terminal connected to the internal source node and gate terminal connected to the internal gate node; and a voltage limiting element connected between the internal gate and source nodes. A driving stage, voltage-referred to the internal source node, drives the switching of the bidirectional switch, as a function a first and a second driving signals, and has a driving transistor and a switching transistor connected to each other in inverter configuration.