Patent attributes
A system and a method selectively switch between two different voltage supplies supplying a common node. A first of the voltage supplies is coupled to the common node by a first switch and a second of the voltage supplies is coupled to the common node by a second switch. The switching device comprises: a feedback network comprising a high-pass filter for filtering a signal at the common node and outputting the filtered signal as a feedback signal; a timing controller coupled to at least one of the first and second voltages supplies for determining when to switch between said first and second power supplies; a ring switch controller for applying a first control signal to the first switch for selectively enabling and disabling the first switch in response to the timing controller and the feedback signal; and a battery switch controller for applying a second control signal to the second switch for selective enabling and disabling the second switch in response to the timing controller and the feedback signal. The method comprises the steps of: receiving a request to switch between the first and second voltage supplies; gradually removing the voltage supply coupled to the common node; gradually applying the other of said voltage supplies; and filtering a signal at said common node for detecting noise.
