Normally-off DC/DC Converter Circuit Using 2DEG Transistors
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Solution Overview
Problem
Existing DC/DC converter circuits face challenges in reducing switching device loss and simplifying the circuit structure, particularly in preventing through-current flow when power is not fully supplied, which can damage transistors and complicate the circuit.
Innovation Solution
A DC/DC converter circuit utilizing a normally-off high-side transistor and a normally-on low-side transistor, both formed in compound semiconductor substrates with two-dimensional electron gas layers, eliminating the need for a protection circuit and reducing switching device loss by optimizing transistor configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a protection circuit is newly formed to suppress through-current, then transistor damage is prevented, but circuit complexity increases
Solution Approach 1:
The high-side switch is designed as a normally-off type transistor that automatically prevents through-current flow by its inherent electrical characteristics. When the gate-source voltage is below the threshold voltage, the transistor remains off and blocks current flow without requiring external protection circuits. This self-protecting mechanism eliminates the need for additional protection components while maintaining transistor safety.
Solution Approach 2:
The invention changes the operational parameter of the high-side switch from normally-on to normally-off type. By controlling the gate-source voltage parameter to be below the threshold voltage during normal operation, the transistor inherently blocks through-current. This parameter change transforms the transistor's default state to provide automatic protection against through-current damage.
2Loss of energy
If conventional switching devices are used, then circuit simplicity is maintained, but power source efficiency is insufficient
Solution Approach 1:
The invention employs a composite transistor structure combining a semiconductor layer with a two-dimensional electron gas layer formed at the interface between the semiconductor layer and an adjacent layer. This composite structure leverages the unique electrical properties of the two-dimensional electron gas to achieve low on-resistance and reduced switching losses, significantly improving power source efficiency compared to conventional single-material transistors.
Solution Approach 2:
The invention introduces a two-dimensional electron gas layer at the interface between the semiconductor layer and the adjacent layer to create a region of high electron concentration. This local enhancement of electrical properties reduces the on-resistance specifically in the channel region where current flows, thereby minimizing conduction losses without affecting other parts of the circuit.
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 configuration improves power source efficiency while simplifying the circuit structure, reducing switching device loss and preventing through-current flow without additional protection circuits, thereby enhancing operational reliability and efficiency.
Implementation Method 1
a first compound semiconductor substrate having a two-dimensional electron gas layer
Data Source
AI summary
Provided is a semiconductor device including a DC/DC converter circuit, wherein the DC/DC converter circuit includes a transistor of a normally-off type, having a first drain electrode connected town input terminal and a first source electrode connected to an output terminal, which is formed in a first compound semiconductor substrate having a two-dimensional electron gas layer, and a transistor having a second drain electrode connected to the first source electrode and a grounded second source electrode.