High-Voltage MOSFET Output Stage With Reverse Bias Leakage Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional electrical output stages for high-voltage applications suffer from significant leakage current when transistors are in their high-impedance state, which degrades system performance, and the inclusion of high-voltage switches introduces non-linear signal distortion and compromises on size, resistance, and leakage current.
Innovation Solution
The use of first and second enhancement mode, metal oxide semiconductor field effect transistors (MOSFETs) are electrically coupled in series between a power rail and an output node, with reverse bias circuitry to mitigate leakage current by using a first and second enhancement mode, metal oxide semiconductor field effect transistors (MOSFETs) are electrically coupled in series between a power rail and an output node, with reverse a source, and a source, and a source, and a source, with reverse bias circuitry to bias the source of the second MOSFET, minimizing leakage current without the need for a high-voltage switch.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional high-voltage transistors are used in electrical output stages, then high-voltage operation is enabled, but significant leakage current occurs when transistors are in high-impedance state
Solution Approach 1:
The patent divides a single high-voltage transistor into multiple series-connected transistors (first transistor, second transistor, third transistor) sharing the voltage blocking task. This segmentation allows each transistor to operate at lower individual voltages while collectively handling high-voltage, significantly reducing leakage current in the off-state compared to a single high-voltage transistor.
Solution Approach 2:
The patent introduces intermediate voltage-blocking elements (such as diodes or resistors) between the series-connected transistors to distribute and balance the voltage across each transistor. These intermediaries ensure proper voltage sharing and prevent any single transistor from experiencing excessive voltage stress, enabling reliable high-voltage operation with reduced leakage.
2Loss of energy
If high-voltage switches are added to reduce leakage current, then leakage current is reduced, but non-linear signal distortion is introduced and device complexity increases
Solution Approach 1:
The patent combines the voltage-blocking function and the signal transmission function into the same series-connected transistor structure. The series transistors naturally block high voltage when off while maintaining linear signal transmission when on, eliminating the need for separate high-voltage switch components and their associated non-linear distortion problems.
Solution Approach 2:
The series-connected transistor configuration serves multiple functions simultaneously: it blocks high voltage, reduces leakage current, and maintains linear signal transmission. This multi-functionality eliminates the need for additional dedicated high-voltage switch components, thereby reducing overall device complexity.
3Loss of energy
If high-voltage switches are used to mitigate leakage current, then leakage current is reduced, but compromises on size and on-resistance are required
Solution Approach 1:
By segmenting the high-voltage blocking function across multiple transistors, each transistor can be optimized for lower voltage and smaller size while maintaining low on-resistance. The series connection achieves the same high-voltage blocking capability as a single large transistor would provide, but with reduced individual device sizes and lower overall resistance.
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 effectively minimizes leakage current during the off-state of the electrical output stage, eliminating the need for high-voltage switches and their associated drawbacks, thereby maintaining signal integrity and optimizing performance.
Implementation Method 1
reverse bias circuitry configured to bias a source of the second MOSFET such that a gate of the second MOSFET is reversed biased with respect to the source of the second MOSFET
Data Source
AI summary
An electrical output stage suitable for high-voltage operation, including a first MOSFET, a second MOSFET, a first switching device, a second switching device, and reverse bias circuitry. The first and second MOSFETs are electrically coupled in series between a power rail and an output node. The first switching device is configured to control a gate-to-source voltage of the first MOSFET, and the second switching device is configured to control a gate-to-source voltage of the second MOSFET. The reverse bias circuitry is configured to bias a source of the second MOSFET such that a gate of the second MOSFET is reversed biased with respect to the source of the second MOSFET, when each of the first MOSFET and the second MOSFET is in its respective off-state.