초록 ▼

A secondary battery protection circuit detects at least one of an over-discharge state, an over-charge state, and an over-current state of a secondary battery and performs an operation in accordance with the detected state. The secondary battery protection circuit comprises a blind time setting circ

A secondary battery protection circuit detects at least one of an over-discharge state, an over-charge state, and an over-current state of a secondary battery and performs an operation in accordance with the detected state. The secondary battery protection circuit comprises a blind time setting circuit constituted by an IC for setting a blind time in accordance with the detected state. The blind time setting circuit has a switching circuit for setting a blind time for a functional test that is shorter than a preset blind time.

대표청구항 ▼

1. A secondary battery protection circuit which detects at least one of an over-discharge state, an over-charge state, and an over-current state of a secondary battery to perform an operation in accordance with the detected state and which has a blind time setting circuit constituted by an IC for se

1. A secondary battery protection circuit which detects at least one of an over-discharge state, an over-charge state, and an over-current state of a secondary battery to perform an operation in accordance with the detected state and which has a blind time setting circuit constituted by an IC for setting a blind time in accordance with the detected state, wherein the blind time setting circuit comprises a switching circuit for setting a blind time for a functional test that is shorter than a preset blind time. 2. A secondary battery protection circuit according to claim 1, wherein the blind time setting circuit includes a clock generation circuit for generating clocks and n (n is an integer equal to or greater than 1) stages of flip-flop circuits for dividing the clocks; the period of the clock is determined by a current I that flows through the clock generation circuit; and the switching circuit includes a current mirror circuit connected to the clock generation circuit for controlling the current I. 3. A secondary battery protection circuit according to claim 2, wherein the blind time setting circuit is constituted by an IC; the IC has a plurality of input and output terminals; and the current mirror circuit is activated by changing connections between predetermined terminals among the plurality of input and output terminals. 4. A secondary battery protection circuit according to claim 3, wherein the clock generation circuit includes N (N is an integer equal to or greater than 2) stages of charge/discharge sections each including a transistor for charging and discharging, a capacitor connected in parallel to the transistor, and a first current mirror transistor connected in series to the transistor for charging and discharging; and the current mirror circuit includes N stages of second current mirror transistors which are connected to lines of the capacitors at the N respective stages to increase the current I flowing through the lines, thereby reducing the period of the clock. 5. A secondary battery protection circuit according to claim 4, wherein the secondary battery is a lithium ion battery. 6. A secondary battery unit provided with the secondary battery protection circuit claimed in claim 1.