Patent ID: 6498630
Filing Date: 2002-12-24
Classification: H04N

Abstract:
An x-ray protection circuit comprising:a reset circuit receiving a supply voltage, said reset circuit to detect an occurrence of a parasitic spike on the supply voltage, or on a ground, or on a substrate, and to generate a restore-maintain horizontal output pulse signal whilst power is on; a comparator to provide a comparator output signal when an x-ray input voltage exceeds a reference voltage; and a bistable device having a reset input coupled to receive said restore-maintain horizontal output pulse signal and a set input coupled to receive said comparator output signal, and provide a memorized x-ray output signal to disable a horizontal output pulse when the x-ray input voltage exceeds the reference voltage, wherein, when the parasitic spike is detected on the supply voltage, or on the ground, or on the substrate, the reset input of said bistable device is triggered, by said restore-maintain horizontal output pulse, to restore or maintain said horizontal output pulse, said bistable circuit giving priority to the reset input of said bistable device, when the set input and the reset input of said bistable device are activated substantially simultaneously.