A Micropower Self-Clocked Camera-on-a-Chip

This paper addresses the development of a micropower 176 x 144 CMOS active pixel image sensor that dissipates one-to-two orders of magnitude less power than current state of the art CMOS image sensors. The chip operates from a 1.5 V voltage source and the power consumption measured for the chip running from an internal 25.2 MHz clock yielding 30 frames per second is about 550 μW. This amount enables the sensor to be run from a watch battery. It is believed that this chip is the world’s lowest power image sensor and the first image sensor designed for a watch battery operation. The camera-on-a-chip operates as a self-clocked 3-pin sensor (GND, VDD (1.2 1.7 V), and DATAOUT). The die occupies 4 mm of silicon.