Patent ID: 6643111
Filing Date: 2003-11-04
Classification: G01D,G01R

Abstract:
A transducer device that provides a signal output, and is connected to a ground conductor and to a voltage conductor, said transducer device comprising:a fault alarm circuit that forces a prescribed potential at said signal output through a first p-channel-depletion-transistor situated in an n-well of a p-conducting substrate, when there is a break in the ground conductor, said n-well of said p-channel-depletion-transistor is connected to said operating voltage connection via a first resistor, a gate connection of said p-channel-depletion-transistor is coupled to and controlled by a charge pump, which is situated between the operating voltage connection and the ground connection, and in a normal operating state, the output voltage of said charge pump is sufficiently high to block said p-channel-depletion-transistor, whereas, if the ground conductor has a break, said p-channel-depletion-transistor conducts and pulls said signal output approximately to the operating voltage to protect said transducer device, wherein said signal output is connected to the ground connection through a second resistor.