Charge and discharge control circuit, and charge and discharge control method

1. A charge and discharge control circuit to control charge and discharge of a secondary battery, comprising:

a power terminal configured to receive power from the secondary battery;

an overcurrent detection terminal configured to detect an overcurrent of the secondary battery;

an abnormality detection part set with predetermined delay times for detecting an overcharge, an overdischarge, and an overcurrent; and

a mode control part configured to control a plurality of modes of operation,

wherein the mode control part includes

managing a normal mode in which voltages at the power terminal and the overcurrent detection terminal are monitored by the abnormality detection part, a time-shortening mode in which the predetermined delay times of the abnormality detection part are shortened, and a protection mode in which a signal is output to stop a charge current or a discharge current when an abnormality is detected by the abnormality detection part in the normal mode;

making a transition from the normal mode to the time-shortening mode when the voltage at the power terminal monitored by the abnormality detection part exceeds a first predetermined voltage;

making a transition from the time-shortening mode to the protection mode when either one of the overdischarge and the overcurrent is detected by the abnormality detection part;

wherein the protection mode includes an overcharge protection mode in which the overcharge current is detected by one of the predetermined delay times of the abnormality detection part,

wherein the time-shortening mode includes a time-shortening monitor mode in which voltages at the power terminal and the overcurrent detection terminal are monitored by the abnormality detection part, and a time-shortening overcharge voltage detection mode in which the signal to stop the charge current is output when the overcharge is detected by the abnormality detection part, and

making a transition to the time-shortening overcharge voltage detection mode when the overcharge is detected in the time-shortening monitor mode, making a transition to the time-shortening monitor mode when the overcharge detection of the abnormality detection part ends, and making a transition to the overcharge protection mode when the voltage at the overcurrent detection terminal is lower than a second predetermined voltage in the time-shortening overcharge voltage detection mode.

2. The charge and discharge control circuit as claimed in claim 1 , further comprising:

a signal output part configured to output a signal to stop the charge current or the discharge current when the abnormality is detected by the abnormality detection part in the normal mode,

wherein the signal output part outputs the signal to stop the charge current when the abnormality detection part detects the overcharge in the time-shortening overcharge voltage detection mode.

3. A charge and discharge control circuit to control charge and discharge of a secondary battery, comprising:

a power terminal configured to receive power from the secondary battery;

an overcurrent detection terminal configured to detect an overcurrent of the secondary battery;

an abnormality detection part set with predetermined delay times for detecting an overcharge, an overdischarge, and an overcurrent; and

a mode control part configured to control a plurality of modes of operation,

wherein the mode control part includes

managing a normal mode in which voltages at the power terminal and the overcurrent detection terminal are monitored by the abnormality detection part, a time-shortening mode in which the predetermined delay times of the abnormality detection part are shortened, and a protection mode in which a signal is output to stop a charge current or a discharge current when an abnormality is detected by the abnormality detection part in the normal mode;

making a transition from the normal mode to the time-shortening mode when a voltage at the overcurrent detection terminal monitored by the abnormality detection part exceeds a first predetermined voltage;

making a transition from the time-shortening mode to the protection mode when either one of the overdischarge and the overcurrent is detected by the abnormality detection part;

wherein the protection mode includes a charge overcurrent protection mode in which the charge overcurrent is detected by one of the predetermined delay times of the abnormality detection part,

wherein the time-shortening mode includes a time-shortening monitor mode in which the voltages at the power terminal and the overcurrent detection terminal are monitored by the abnormality detection part, and a time-shortening charge overcurrent detection mode in which the signal to stop the charge current is output when the charge overcurrent is detected by the abnormality detection part, and

making a transition to the time-shortening charge overcurrent detection mode when the charge overcurrent is detected by the abnormality detection part in the time-shortening monitor mode, making a transition to the time-shortening monitor mode when the charge overcurrent detection of the abnormality detection part ends, and making a transition to the charge overcurrent protection mode when the voltage at the power terminal monitored by the abnormality detection part exceeds a second predetermined voltage in the time-shortening charge overcurrent detection mode.

4. The charge and discharge control circuit as claimed in claim 3 , further comprising:

a signal output part configured to output a signal to stop the charge current or the discharge current when the abnormality is detected by the abnormality detection part in the normal mode,

wherein the signal output part outputs the signal to stop the charge current when the abnormality detection part detects the charge overcurrent in the time-shortening charge overcurrent detection mode.

5. A charge and discharge control method to control charge and discharge of a secondary battery by a charge and discharge control circuit that includes a power terminal configured to receive power from the secondary battery, an overcurrent detection terminal configured to detect an overcurrent of the secondary battery, an abnormality detection part set with predetermined delay times for detecting an overcharge, an overdischarge, and an overcurrent, and a mode control part configured to control a plurality of modes of operation, the charge and discharge control method comprising:

managing, by the mode control part, a normal mode in which voltages at the power terminal and the overcurrent detection terminal are monitored by the abnormality detection part, a time-shortening mode in which the predetermined delay times of the abnormality detection part are shortened, and a protection mode in which a signal is output to stop a charge current or a discharge current when an abnormality is detected by the abnormality detection part in the normal mode;

making, by the mode control part, a transition from the normal mode to the time-shortening mode when the voltage at the power terminal monitored by the abnormality detection part exceeds a first predetermined voltage;

making, by the mode control part, a transition from the time-shortening mode to the protection mode when either one of the overdischarge and the overcurrent is detected by the abnormality detection part;

wherein the protection mode includes an overcharge protection mode in which the overcharge current is detected by one of the predetermined delay times of the abnormality detection part,

wherein the time-shortening mode includes a time-shortening monitor mode in which voltages at the power terminal and the overcurrent detection terminal are monitored by the abnormality detection part, and a time-shortening overcharge voltage detection mode in which the signal to stop the charge current is output when the overcharge is detected by the abnormality detection part, and

making, by the mode control part, a transition to the time-shortening overcharge voltage detection mode when the overcharge is detected by the abnormality detection part in the time-shortening monitor mode, a transition to the time-shortening monitor mode when the overcharge detection of the abnormality detection part ends, and a transition to the overcharge protection mode when the voltage at the overcurrent detection terminal monitored by the abnormality detection part is lower than a second predetermined voltage in the time-shortening overcharge voltage detection mode.

6. The charge and discharge control method as claimed in claim 5 , wherein the charge and discharge control circuit further includes a signal output part configured to output a signal to stop the charge current or the discharge current when the abnormality is detected by the abnormality detection part in the normal mode, and wherein the charge and discharge control method further comprises:

outputting, from the signal output part, the signal to stop the charge current when the abnormality detection part detects the overcharge in the time-shortening overcharge voltage detection mode.

7. A charge and discharge control method to control charge and discharge of a secondary battery by a charge and discharge control circuit that includes a power terminal configured to receive power from the secondary battery, an overcurrent detection terminal configured to detect an overcurrent of the secondary battery, an abnormality detection part set with predetermined delay times for detecting an overcharge, an overdischarge, and an overcurrent, and a mode control part configured to control a plurality of modes of operation, the charge and discharge control method comprising:

managing, by the mode control part, a normal mode in which voltages at the power terminal and the overcurrent detection terminal are monitored by the abnormality detection part, a time-shortening mode in which the predetermined delay times of the abnormality detection part are shortened, and a protection mode in which a signal is output to stop a charge current or a discharge current when an abnormality is detected by the abnormality detection part in the normal mode;

making, by the mode control part, a transition from the normal mode to the time-shortening mode when a voltage at the overcurrent detection terminal monitored by the abnormality detection part exceeds a second predetermined voltage;

making, by the mode control part, a transition from the time-shortening mode to the protection mode when either one of the overdischarge and the overcurrent is detected by the abnormality detection part;

wherein the protection mode includes a charge overcurrent protection mode in which the charge overcurrent is detected by one of the predetermined delay times of the abnormality detection part,

wherein the time-shortening mode includes a time-shortening monitor mode in which the voltages at the power terminal and the overcurrent detection terminal are monitored by the abnormality detection part, and a time-shortening charge overcurrent detection mode in which the signal to stop the charge current is output when the charge overcurrent is detected by the abnormality detection part, and

making, by the mode control part, a transition to the time-shortening charge overcurrent detection mode when the charge overcurrent is detected by the abnormality detection part in the time-shortening monitor mode, a transition to the time-shortening monitor mode when the charge overcurrent detection of the abnormality detection part ends, and a transition to the charge overcurrent protection mode when the voltage at the power terminal monitored by the abnormality detection part exceeds a second predetermined voltage in the time-shortening charge overcurrent detection mode.

8. The charge and discharge control method as claimed in claim 7 , wherein the charge and discharge control circuit further includes a signal output part configured to output a signal to stop the charge current or the discharge current when the abnormality is detected by the abnormality detection part in the normal mode, and wherein the charge and discharge control method further comprises:

outputting, from the signal output part, the signal to stop the charge current when the abnormality detection part detects the charge overcurrent in the time-shortening charge overcurrent detection mode.