Device that can be rendered useless and method thereof

摘要

In one form a device having an integrated circuit is rendered useless by providing a piezo element coupled to a voltage terminal of the integrated circuit of the device. A render useless signal is generated by any of several ways. The piezo element, in response to the render useless signal, renders in any one of several ways the device to be rendered useless. The piezo element, when disturbed, generates a voltage which is provided to the voltage terminal of the integrated circuit, the voltage being sufficiently high to render useless at least a portion of the integrated circuit. In other forms the render useless signal renders MRAM circuitry within the device useless by moving a magnetic field across the MRAM circuitry to vary resistance of memory reference cells. In one form the magnetic field is moved by spring-loading or pivoting a magnet that is released by the piezo element.