Power Supply Module Overcurrent Protection Circuit
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Solution Overview
Problem
Existing DC-DC conversion modules face challenges in accurately performing overcurrent protection in a timely manner, leading to potential overstress damage to power elements due to complex signal transmission from the secondary to the primary side.
Innovation Solution
A power module with a control circuit that includes a sampling and amplification circuit, comparison circuit, and processing circuit to sample, amplify, and compare current outputs with thresholds, enabling precise overcurrent protection through mechanisms like slow overcurrent, backflow current, and signal-by-signal current limiting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If signal transmission from secondary side to primary side is used for overcurrent detection, then overcurrent protection can be implemented, but the system complexity increases and response timing is delayed
Solution Approach 1:
The patent introduces an intermediary current detection circuit on the primary side that indirectly monitors secondary side overcurrent conditions through transformer coupling. The detection circuit uses a current transformer to sense the primary current, which correlates with secondary load conditions, providing overcurrent protection without direct secondary-to-primary signal transmission.
Solution Approach 2:
The patent segments the overcurrent detection function into separate primary-side and secondary-side circuits. The primary side contains the detection circuit that independently monitors current conditions, while the secondary side contains only the power conversion components. This segmentation eliminates the need for complex inter-side signal transmission.
2Device complexity
If simple current monitoring is used, then system complexity is reduced, but measurement precision of overcurrent state deteriorates
Solution Approach 1:
The patent replaces simple mechanical current sensing with an electromagnetic field-based current transformer detection system. The current transformer uses electromagnetic induction to accurately sense current magnitude and generate proportional detection signals, providing high measurement precision while maintaining circuit simplicity.
Solution Approach 2:
The patent changes the detection parameter from direct voltage measurement to current transformation ratio measurement. By using the current transformer's turns ratio to scale down primary current to a measurable secondary current, the system achieves high precision overcurrent detection with simple circuitry.
Data Source
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AI summary
Embodiments of this application disclose a power module, a router, a switch, and an electronic device. The power module includes a control circuit and a voltage conversion circuit capable of supplying power to a load. The control circuit may include a sampling and amplification circuit, a comparison circuit, and a processing circuit. The sampling and amplification circuit is configured to sample a first current output by the voltage conversion circuit, amplify the first current based on a preset coefficient, and output a second current. The comparison circuit may compare the second current with a first overcurrent threshold, and output a first comparison signal when the second current is greater than or equal to the first overcurrent threshold. The processing circuit may stop outputting a pulse signal to the voltage conversion circuit when receiving the first comparison signal, to perform overcurrent protection on the voltage conversion circuit. In this application, a problem in the conventional technology that overcurrent protection cannot be accurately performed on the power module in a timely manner can be resolved, and security and stability of the power module can be improved.