Adhesion detection circuit of charging and discharging MOS (Metal Oxide Semiconductor) tube and detection method thereof

Abstract

The invention relates to an adhesion detection circuit of a charge-discharge MOS tube and a detection method thereof. The circuit comprises a control unit, a first detection unit, a second detection unit, a charge MOS tube Q2 and a discharge MOS tube Q1. The control unit is respectively connected with the first detection unit, the second detection unit, the charging MOS tube Q2 and the discharging MOS tube Q1; the control unit is used for controlling the connection or disconnection of the charging MOS tube Q2 and the discharging MOS tube Q1, performing analysis according to signals input by the first detection unit and the second detection unit, and feeding back an analysis result to specified equipment. The first detection unit is used for detecting a collector voltage signal of the charging MOS tube Q2 when the control unit controls the charging MOS tube Q2 to be disconnected; and the second detection unit is used for detecting a collector voltage signal of the discharge MOS tube Q1 when the control unit controls the discharge MOS tube Q1 to be disconnected. According to the invention, the adhesion condition of the charge and discharge MOS tubes can be accurately detected at low cost.

Description

technical field [0001] The present invention relates to a charging and discharging circuit, more specifically to a charging and discharging MOS tube adhesion detection circuit and a detection method thereof. Background technique [0002] The protection board is used in the charging and discharging process of the battery. The function of the protection board is essentially realized by turning on and off the discharge MOS tube and the charge MOS tube on the main control circuit. [0003] During the use of the battery, there will always be over-current and short-circuit states, and the battery-containing board will perform logic control based on the sampling current. When an overcurrent is detected, the charge MOS tube is turned off during charging, and the discharge MOS tube is turned off during discharge; when a short circuit is detected, both the charge MOS tube and the discharge MOS tube are turned off. However, since the current in this state is relatively large, the MOS ...

AI Technical Summary

Problems solved by technology

However, since the current in this state is relatively large, the MOS tube may be damaged, and the damaged mode may be an off state or an on state. If there is no adhesion detection function, the current MOS cannot be identified. In the case of the tube, if the MOS tube is disconnected, the battery cannot output, which is relatively safe; but if the MOS tube is short-circuited, the damage mode

When a large current needs to be protected, the control system cannot control the disconnection of the MOS tube, which will bring a great risk of tube explosion and may damage the battery to a certain extent.

[0004] The reason for sticking is because the load is large, the current is large, and the voltage generated when disconnecting is high enough to generate a certain amount of heat, causing the contact points to melt, and then after rapid cooling, the contacts cannot be completely disconnected, and a sticking state occurs. However, the current adhesion detection is used on the relay, and the adhesion detection on the MOS tube is not used.

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