Charging protection circuit, driving method, chip, package structure, and electronic device
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Solution Overview
Problem
Existing charging circuits face challenges in providing stable bi-directional protection during both wired and wireless charging processes, particularly in managing over-voltage protection across the power supply and load ends, due to issues like back-gate effects and channel punch-through, which affect the turn-on resistance and breakdown voltage capabilities of switching transistors.
Innovation Solution
The proposed charging protection circuit employs a bi-directional switching transistor with a pull-up and pull-down circuit configuration, adjusting the substrate electrode potential to ensure optimal turn-on and breakdown characteristics by using resistors and clamping diodes, and integrating these components to minimize back-gate effects and enhance breakdown voltage capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the substrate electrode potential is not adjusted, then the device structure remains simple, but the turn-on resistance increases due to back-gate effect
Solution Approach 1:
The patent introduces a pull-up circuit as an intermediary component between the substrate electrode and the power supply voltage. This pull-up circuit actively adjusts the substrate electrode potential to a threshold value, serving as a mediator that resolves the conflict between maintaining simple structure and achieving low turn-on resistance. The pull-up circuit compensates for the back-gate effect by providing the necessary potential adjustment without requiring fundamental changes to the transistor structure.
2Reliability
If the substrate electrode potential is not adjusted, then the circuit configuration remains simple, but the breakdown voltage capability is insufficient due to channel punch-through
Solution Approach 1:
The patent applies preliminary action by adjusting the substrate electrode potential before the transistor operates in breakdown conditions. The pull-up circuit pre-establishes the appropriate potential level on the substrate electrode, which prevents channel punch-through and enhances breakdown voltage capability before any harmful effects can occur. This proactive approach avoids the need for complex protective circuits that would only activate during breakdown events.
3Reliability
If a dual-gate bi-directional conduction device is used, then the blocking function is improved, but the characteristic resistance is larger
Solution Approach 1:
The patent changes the key parameter of substrate electrode potential to optimize the performance of the single-gate bi-directional conduction device. By adjusting the substrate electrode potential to a threshold value through the pull-up circuit, the device achieves blocking functionality comparable to dual-gate devices while maintaining lower characteristic resistance. This parameter change approach allows the single-gate device to operate in an optimized state that balances blocking capability and resistance characteristics.
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 ensures stable bi-directional protection by maintaining low turn-on resistance and sufficient breakdown voltage, improving the efficiency and reliability of the charging process across various charging scenarios.
Implementation Method 1
When the first switching transistor is turned on, if the potential of the substrate electrode is low relative to the first drain electrode and the second drain electrode, back-gate effect causes an increase of a turn-on resistance of the first switching transistor
Implementation Method 2
When the first switching transistor is turned off, if the potential of the substrate electrode is high relative to the first drain electrode and the second drain electrode, the substrate electrode induces a positive charge, which causes a narrower width of a depletion region at a channel. As a result, channel punch-through easily occurs in the first switching transistor
Data Source
AI summary
Embodiments of this application relate to the field of power supply system technologies, and provide a charging protection circuit, a driving method, a chip, a package structure, and an electronic device, to provide a charging protection circuit with stable bi-directional protection effect. The charging protection circuit includes a first switching transistor and a pull-up circuit. For example, the first switching transistor is a bi-directional HEMTs device, and includes a first drain electrode, a second drain electrode, a first gate electrode, and a substrate electrode. The first drain electrode is configured to receive a signal from the second drain electrode, the second drain electrode is configured to receive a signal from the first drain electrode, and the first gate electrode is configured to control the first switching transistor to be turned on or turned off.