Non-Isolating AC-DC Voltage Converter with Valley Switching
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Solution Overview
Problem
Conventional non-isolating AC-DC voltage converters face challenges with low power efficiency due to high input voltage from mains power, and they struggle with integration and isolation between high and low voltage regions, leading to complex and costly systems.
Innovation Solution
A non-isolating AC-DC voltage converting system comprising a first voltage converting module that turns on a power transistor at valley regions of the bus voltage to generate an interim voltage, and a second module that converts this voltage into a regulated direct-current output using a DC-DC converter, with components distributed across separate semiconductor substrates to reduce complexity and power loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If isolated voltage converters are used to handle high input voltage, then safety and reliability are improved, but cost and system complexity increase due to voltage transformer
Solution Approach 1:
The system is divided into two separate semiconductor substrates: a first substrate handling high voltage components and a second substrate handling low voltage components. This segmentation allows each substrate to be optimized for its specific voltage range, reducing the need for complex isolation structures while maintaining safety and reliability.
Solution Approach 2:
An interim voltage is introduced as an intermediate stage between the high voltage input and the low voltage output. The first voltage converting module converts high voltage to this interim voltage, which is then further converted to the final low voltage output by the second module. This intermediary approach enables gradual voltage transformation without requiring direct high-voltage-to-low-voltage conversion, reducing complexity.
2Device complexity
If non-isolating AC-DC voltage converters are used to reduce complexity, then system complexity is reduced, but power efficiency deteriorates due to high voltage of mains power
Solution Approach 1:
The voltage conversion process is segmented into two stages across separate substrates. The first stage handles high-voltage-to-interim-voltage conversion with optimized power transistors, and the second stage handles interim-voltage-to-low-voltage conversion. This segmentation allows each stage to operate in its optimal efficiency range, preventing the power losses that would occur in a single-stage non-isolating converter.
Solution Approach 2:
The system changes the voltage parameter in two distinct steps rather than one. By converting high voltage to an interim voltage level first, then to the final low voltage level, the system maintains higher power efficiency at each conversion stage compared to a direct single-stage conversion, while still avoiding the complexity of isolation transformers.
3Adaptability or versatility
If high voltage and low voltage are integrated on the same semiconductor die, then integration is improved, but isolation between voltage regions becomes challenging
Solution Approach 1:
The invention physically segments the integrated circuit into two separate semiconductor substrates. The first substrate contains high-voltage components (first voltage converting module), while the second substrate contains low-voltage components (second voltage converting module). This physical segmentation eliminates the need for complex on-die isolation structures while maintaining high integration within each substrate for its respective voltage range.
Solution Approach 2:
The system uses a modular architecture where the voltage conversion functionality is copied across two separate substrates rather than attempting to integrate all functions on a single die. Each substrate is a self-contained module that can be independently designed, fabricated, and tested, then combined to form the complete system. This modular copying approach simplifies the isolation challenge while maintaining integration benefits.
Data Source
AI summary
A non-isolating AC-DC voltage converting system has two voltage converters. The first voltage converter receives a bus voltage and turns on a power transistor when the bus voltage is at valley regions and to provide an interim voltage which is lower than the bus voltage. The second voltage converter receives the interim voltage and provides an output voltage of the AC-DC voltage converting system.