US Patent 10910851 Overcurrent, overcharge, and overdischarge detection and responsive switch control

A charge/discharge control circuit includes a control circuit which outputs a control signal to a charge control terminal and a discharge control terminal respectively, a charge/discharge monitoring circuit which monitors charge/discharge of a secondary battery, a charger detection circuit connected to a charger detection terminal and configured to detect a charger connection, and a load open detection circuit connected to the charger detection terminal and configured to detect a state of a load. In response to reception of a signal to instruct turning on of a charge control FET from the charger detection circuit, the control circuit turns on the charge control FET even when the control circuit turned off the charge control FET in response to the signal to instruct turning off of the charge control FET from the charge/discharge monitoring circuit.