Substrate switching circuit for lithium battery protection

Abstract

The invention provides a substrate switching circuit for lithium battery protection, and the substrate switching circuit for lithium battery protection comprises a lithium battery protection chip, a NMOS tube M0, a substrate control circuit and a grid control circuit; the lithium battery protection chip is connected with the substrate of the NMOS tube M0 through the substrate control circuit; thelithium battery protection chip is also connected with a grid of the NMOS tube M0 through the grid control circuit; a drain of the NMOS tube M0 is grounded, and a source of the NMOS tube M0 is outputto a cathode of the battery. The substrate switching circuit can be realized by only one NMOS tube M0, relative to a scheme of needing two external NMOS tubes in the existing technology, cost is reduced. According to the substrate switching circuit provided by the invention, size of the NMOS tube M0 also can be selected optionally according to specific situations, and relative to the scheme of using a fully integrated chip in the existing technology, the substrate switching circuit has higher flexibility.

Description

technical field [0001] The invention belongs to the technical field of electronic information, and in particular relates to a substrate switching circuit for lithium battery protection. Background technique [0002] The circuit diagram of the existing lithium battery protection circuit, such as figure 1 , figure 2 shown. figure 1 It is to add two external NMOS tubes on the periphery of the lithium battery protection chip, figure 2 It uses a fully integrated chip, that is, the MOS tube is integrated into the chip. [0003] figure 1 The lithium battery protection circuit can flexibly choose the size of the external NMOS tube, which has high flexibility, but because of the use of two external NMOS tubes, the cost is relatively high. figure 2 The lithium battery protection circuit can effectively reduce the cost by integrating NMOS, but it cannot choose the size of the external NMOS tube, and the flexibility is poor. Contents of the invention [0004] Aiming at the de...

AI Technical Summary

Problems solved by technology

[0003] figure 1 The lithium battery protection circuit can flexibly choose the size of the external NMOS tube, which has high flexibility, but because of the use of two external NMOS tubes, the cost is high

figure 2 The lithium battery protection circuit can effectively reduce the cost by integrating NMOS, but it cannot choose the size of the external NMOS tube, and the flexibility is poor

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