Charging and discharging MOS protection circuit

Abstract

The invention discloses a charging and discharging MOS protection circuit. The charging and discharging MOS protection circuit comprises a battery and a protection circuit. The protection circuit comprises a current sampling resistor RS, a discharge control mosQD and a charge control mosQC. The protection circuit also comprises a discharge mos protection voltage-regulator tube ZD, a discharge mosprotection capacitor CD, a charge mos protection voltage-regulator tube ZC, and a charge mos protection capacitor CC, wherein the current sampling resistor RS is used for measuring current by a CPU; and the discharge mos protection voltage-regulator tube ZD and the charge mos protection voltage-regulator tube ZC provide voltage-limiting protection. According to the invention, the discharge mos protection capacitor CD and the charge mos protection capacitor CC have peak absorption capability; the capacitors are matched with the discharge mos protection voltage-regulator tube ZD and the charge mos protection voltage-regulator tube ZC to protect a mos, the faster the cut-off is, the higher the back voltage is, and after the mos is cut off, the change rate of the current is reduced by chargingand discharging the capacitors, so that the back voltage is reduced.

Description

technical field [0001] The invention relates to the technical field of battery charge and discharge, in particular to a charge and discharge MOS protection circuit. Background technique [0002] MOS tube is the abbreviation of MOSFET. MOSFET metal-oxide semiconductor field effect transistor, referred to as metal oxide semiconductor field effect transistor, is generally a metal (metal) - oxide (oxide) - semiconductor (semiconductor) field effect transistor, or called a metal - insulator (insulator) - semiconductor . The source (source) and drain (depletion layer) of the MOS tube can be reversed, and they are all N-type regions formed in the P-type backgate. In most cases, the two regions are the same, even if the two ends are reversed, it will not affect the performance of the device. Such devices are considered symmetrical. Field effect transistors are divided into PMOS transistors and NMOS transistors, which belong to insulated gate field effect transistors. [0003] I...

AI Technical Summary

Problems solved by technology

[0003] In the charging and discharging project of the battery, if there is no protection, when the charging MOS or discharging MOS is cut off at high current, a back pressure will be formed according to the circuit theory. When the back pressure exceeds the withstand voltage of the MOS tube, the MOS tube will be damaged.

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