Secondary battery protection circuit, secondary battery protection device, battery pack, and control method of secondary battery protection circuit

摘要

To prevent unintended operation of an NMOS transistor. A first NMOS transistor and a second NMOS transistor are inserted in series in a current path between a positive electrode of a secondary battery and a positive terminal connected to a power supply terminal of a load or a charger. A secondary battery protection circuit for protecting a secondary battery, wherein each input capacitance of a first NMOS transistor having a gate connected to a charge control terminal and a second NMOS transistor having a gate connected to a discharge control terminal A booster circuit that generates a control voltage boosted by using the drive circuit, a drive circuit that sets each output state of the charge control terminal and the discharge control terminal to a high level with the control voltage, and a detection state of the secondary battery The output state of the charge control terminal and the discharge control terminal from at least three states of high level, low level, and high impedance And a control circuit for selectively to the drive circuit based on the output state, the secondary battery protection circuit. [Selection] Figure 3