Low power event driven pixels with passive difference detection circuitry, and reset control circuits for the same

Abstract

Low power event driven pixels with passive difference detection circuit (and reset control circuits for the same) are disclosed herein. In one embodiment, an event driven pixel comprises a photosensor; a photocurrent-to-voltage converter, and a difference circuit. The difference circuit includes a source follower transistor and a switched-capacitor filter having an input coupled to the photocurrent-to-voltage converter and an output coupled to a gate of the source follower transistor. The switched-capacitor filter includes a first capacitor coupled between the input and the output of the switched-capacitor filter, a second capacitor having a first plate coupled to the output of the switched-capacitor filter, and a reset transistor coupled between a reference voltage and the output of the switched-capacitor filter. The difference circuit is configured generate a difference signal that is indicative of whether the event driven pixel has detected an event in an external scene.