MICROPROCESSOR SELF-POWER DOWN CIRCUIT

摘要

A self-power down circuit for a controller coupled to a battery to obtain power from the battery. The controller has a port, the state of which changes during powering up of the controller. The circuit includes a first switching device including a main current conducting path and a control terminal. The control terminal of the first switching device is coupled to the port for monitoring the state of the port. The circuit further includes a second switching device including a main current conducting path and a control terminal, and a switch. The port is coupled to the battery through the main current conducting path of the second switching device. The control terminal of the second switching device is coupled to the switch for actuation by actuation of the switch. The control terminal of the second switching device is also coupled to the main current conducting paths of the first and second switching devices through first and second voltage dropping elements, respectively.