Protection circuit and protection method for preventing hot plug voltage surge

Abstract

The invention discloses a protection circuit and a protection method for preventing hot plug voltage surge, and relates to the technical field of circuit design. The circuit comprises a power MOS field effect transistor, a photoelectric coupler D2 and an impedance resistor. The power MOS field effect transistor comprises an N-channel power MOS tube Q3 and a P-channel power MOS tube Q2. The cathodeof the input end of the photoelectric coupler D2 is connected with the G electrode of the power MOS tube Q3, and the output end of the collector electrode of the photoelectric coupler D2 is connectedwith the G electrode of the power MOS tube Q2. The impedance resistors comprise a low-impedance resistor R2 and high-impedance resistors R3 and R4. According to the embodiment, the surge protection assembly TVS on a traditional hot plug line is replaced by the protection circuit, the reaction speed of surge protection of the input end is effectively improved, an alarm function during tiny surge is added, and the problem that a rear-end assembly is damaged due to the fact that the surge protection device is too slow in reaction is avoided.

Description

technical field [0001] Embodiments of the present invention relate to the technical field of circuit design, and specifically relate to a protection circuit and a protection method for preventing hot-swap voltage surges. Background technique [0002] Hot-swap controllers are a preferred method of providing highly desirable system protection and electrical management in distributed power systems, especially to meet the stringent requirements of the server market. Features of hot-swap controllers often include safe control of live circuit board insertion and removal, fault monitoring diagnostics and protection, and control of high-precision electrical environments. In practice, if a fault occurs in one line card in a server rack, the fault should remain isolated from that specific line card and affect neither the system backplane nor the other line cards powered by that live backplane. Therefore, to ensure reliability, server system designers must consider the parasitic effec...

AI Technical Summary

Problems solved by technology

However, in actual use, the above protection mechanism still has shortcomings: First, the allowable deviation of the reverse working voltage of the TVS diode is very large. According to the TVS data sheet, the higher the reverse working voltage required by the TVS, the greater the deviation , the required TVS diode cannot be selected more accurately; secondly, when the input voltage slightly increases but does not reach the overvoltage protection of the hot-swap controller, there is no way to notify the control system in time

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