Isolated Gate Driver With AC Coupling for High-Side Voltage Transitions
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Solution Overview
Problem
Existing photovoltaic power systems face challenges in regulating power production between power sources due to high voltage transitions that can damage gate drivers and preceding circuitry, necessitating isolation to prevent faults.
Innovation Solution
An isolated gate driver system is developed, comprising an input stage for DC isolation, a comparator, and a feedback circuit that compares voltage levels and adjusts feedback voltages to manage voltage transitions, ensuring safe operation and efficient control signal delivery to high-side switches.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high-side gate driver is isolated from preceding circuitry using transformers, opto-couplers, capacitors, or Hall-effect sensors, then the reliability is improved by reducing the probability of fault to the gate driver or preceding circuitry, but the device complexity increases due to the additional isolation components required
Solution Approach 1:
The patent introduces an intermediary isolation stage between the high-side gate driver and preceding circuitry. This isolation stage acts as a mediator that transfers control signals while electrically decoupling the two sides, preventing high voltage transitions from damaging the gate driver or preceding circuitry. The intermediary nature of this isolation stage resolves the contradiction by providing fault protection without requiring complex multiple isolation components.
2Reliability
If isolation components are added to protect gate driver from high voltage transitions, then the reliability is improved, but the ease of manufacture deteriorates due to increased assembly and testing complexity
Solution Approach 1:
The patent merges the isolation function with the gate driver circuitry by integrating the isolation stage directly into the gate driver structure. This consolidation allows the isolation components to be manufactured and tested as a single integrated unit, significantly reducing assembly and testing complexity compared to adding separate isolation components. The merging principle resolves the contradiction by maintaining fault protection while simplifying the manufacturing process.
3Adaptability or versatility
If voltage level shifting is implemented to drive high-side MOSFET relative to switching node, then the adaptability is improved for handling varying voltage levels, but the device complexity increases due to additional voltage level conversion circuitry
Solution Approach 1:
The patent designs the gate driver with universal voltage level shifting capability that can handle various voltage levels through a single integrated isolation stage. This multi-functional design allows the same circuit architecture to adapt to different voltage requirements (tens, hundreds, or thousands of volts) without requiring additional voltage conversion circuitry. The universality principle resolves the contradiction by providing voltage level adaptability while maintaining simple device structure.
Data Source
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AI summary
An apparatus comprising an input stage comprising a first input, a second input, a first AC coupler, and a second AC coupler. The first AC coupler is coupled between the first input and a third input. The second AC coupler is coupled between the second input and a fourth input. A comparator coupled to the third input, the fourth input, and an output. The comparator provides an output signal at the output based on a comparison between a level of a first voltage at the third input, and a level of a second voltage at the fourth input. A feedback circuit, coupled to the output, the third input, and the fourth input. The feedback circuit receives the output signal, and provides, based on the output signal, a first feedback voltage to the third input.