Battery activation circuit

A system and method for selectively activating a device based on an activate command. A circuit, in low power mode, listens for an activate command. The activate command includes a preamplifer centering sequence, an interrupt signal, and an activate code. The circuit receives a signal that may or may not be an activate command, self-biases the signal based on the preamplifer centering in the preamp/gain control, then determines whether the interrupt signal is of the proper length in the interrupt circuit. If the interrupt is not the proper length, the process stops. If it is the proper length, the command is recognized as an activate command, and a data slicer compares the activate code to a prestored value. If the activate code matches the prestored value, the device is powered up. If they do not match, the device is not initiated.