Integrated Bidirectional MOSFET Switch With Simplified Gate Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing bidirectional semiconductor devices face challenges in achieving high current, low resistance, and high voltage applications with a reduced device count, particularly in applications requiring AC blocking capabilities, while traditional solutions like back-to-back MOSFETs and dual gate structures increase cell pitch and require multiple gate power supplies.
Innovation Solution
A monolithically integrated bidirectional semiconductor device with sensing, protection, and regulation circuits, featuring a bidirectional power transistor with integrated interface circuits, including transistors and voltage regulators, to regulate gate voltages and provide efficient protection mechanisms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If back-to-back MOSFETs are used for bidirectional switching, then AC blocking capability is achieved, but device count and system complexity increase
Solution Approach 1:
The patent combines two MOSFETs into a single integrated bidirectional switch device that provides AC blocking capability in both directions. The merged device includes a first MOSFET and a second MOSFET with shared components and coordinated control, reducing the overall device count while maintaining bidirectional AC blocking functionality.
Solution Approach 2:
The bidirectional switch is designed as a universal device that can block AC in both directions and control power flow bidirectionally. The device incorporates multiple functions including switching, AC blocking, and protection mechanisms within a single integrated structure, eliminating the need for separate components for each function.
2Area of stationary object
If dual gate structure is used to achieve bidirectional switching with minimum cell pitch, then cell pitch is minimized, but gate driver complexity and power supply requirements increase
Solution Approach 1:
The gate driver is segmented into two independent control circuits: a first control circuit for controlling the first gate terminal and a second control circuit for controlling the second gate terminal. Each control circuit can be independently designed and optimized, reducing the overall complexity while enabling minimum cell pitch through efficient spatial arrangement.
Solution Approach 2:
The device incorporates dynamic control capabilities where the two gates can be independently biased and controlled to achieve bidirectional switching. The gate driver provides dynamic voltage control to each gate terminal, enabling flexible operation modes including bidirectional AC blocking and power flow control with minimum cell pitch.
3Reliability
If gate-to-drain separation distance is increased to enable voltage blocking, then voltage blocking capability is improved, but device area and cell pitch increase
Solution Approach 1:
The device implements different separation distances for different regions: the first gate-to-drain separation distance is optimized for blocking voltage in one direction, while the second gate-to-drain separation distance is optimized for blocking voltage in the opposite direction. This localized optimization allows each gate to provide adequate voltage blocking for its respective direction without requiring uniform large separation distances across the entire device.
Solution Approach 2:
The patent employs different separation distance parameters (first gate-to-drain separation distance and second gate-to-drain separation distance) optimized for respective blocking directions. By changing the separation distance parameter locally for each gate, the device achieves adequate voltage blocking capability in both directions while minimizing overall device area and cell pitch.
Data Source
AI summary
A semiconductor device comprising a first control terminal configured to receive a first control signal; a second control terminal configured to receive a second control signal; and a bidirectional power transistor comprising a first gate terminal, a second gate terminal, a first terminal, and a second terminal, wherein the first gate terminal and second gate terminal are positioned between the first and second terminal, and wherein in use the first and second terminals are configured to operate as source or drain terminals of the bidirectional power transistor. The semiconductor device further comprises an interface circuit monolithically integrated with the bidirectional power transistor and operatively connected to the first control terminal, the second control terminal, the first gate terminal and the second gate terminal, wherein the interface circuit is an actively switchable circuit comprising one or more transistors.