Half-Bridge Circuit With Bidirectional Vertical Transistors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In classical vertical power semiconductor technology, high current switches cannot be implemented on the same die due to the common drain terminal configuration, which restricts the operation of high-side and low-side switches in half-bridge circuits.
Innovation Solution
The implementation of bidirectional vertical power transistors with a common drain configuration allows for the integration of high-side and low-side switches on the same die, enabling them to be switched on complementary states without sharing a common drain, using a cascode arrangement and controlling current flow in both directions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If high current switches are implemented on separate power dice using classical vertical power semiconductor technology, then the common drain terminal configuration is maintained, but the high-side and low-side switches cannot be integrated on the same die
Solution Approach 1:
The patent segments the common drain terminal configuration into separate drain terminals for high-side and low-side switches. This is achieved by providing a first drain terminal for the high-side switch and a second drain terminal for the low-side switch, allowing independent connection and eliminating the integration barrier while maintaining separate power dice architecture.
Solution Approach 2:
The patent introduces a new dimensional approach by adding a body terminal to the vertical power transistors. This body terminal provides an additional connection point that enables independent control of high-side and low-side switches on the same die, effectively adding a degree of freedom to the terminal configuration.
2Ease of operation
If high-side and low-side switches are connected in cascode arrangement with common drain, then vertical power semiconductor technology is used, but complementary switching operation is inhibited
Solution Approach 1:
The patent segments the drain terminal connection by providing separate first and second drain terminals for high-side and low-side switches respectively. This segmentation allows each switch to have independent drain access, enabling complementary switching operations without the constraints of a shared common drain terminal.
Solution Approach 2:
The body terminal acts as an intermediary element that facilitates independent control of the high-side and low-side switches. By providing this additional terminal, the patent enables complementary switching operations while maintaining the cascode arrangement benefits.
3Area of stationary object
If separate power dice are used for high-side and low-side switches, then individual terminal control is possible, but device integration and compactness are reduced
Solution Approach 1:
The patent segments the terminal functions by distinguishing between first drain terminal, second drain terminal, and body terminal. This segmentation allows the high-side and low-side switches to share the same die while maintaining independent terminal control, achieving both compactness and manufacturing feasibility.
Solution Approach 2:
The body terminal serves multiple functions: it enables independent control of both switches, provides an additional current path, and facilitates thermal management. This multi-functionality allows the same die to host both high-side and low-side switches with full control independence.
Data Source
AI summary
A half-bridge circuit comprises a high supply contact and a low supply contact. A half-bridge output contact is connectable to drive a load and has a high-side between the high supply contact and the half-bridge output contact and a low-side between the half-bridge output contact and the low supply contact. A high-side bidirectional vertical power transistor at the high-side has a source connected to the high supply contact, and a low-side bidirectional vertical power transistor at the low-side, transistor has a source connected to the low supply contact. The high-side bidirectional vertical power transistor and low-side bidirectional vertical power transistor are connected in cascode and share a common drain connected to the half-bridge output contact, and are controllable to alternatingly allow a current flow from the high supply contact to the half-bridge output contact or from the half-bridge output contact to the low supply contact.