An adaptive optical sensor

We propose an adaptive optical sensor circuit performing a linear incident-light-to-voltage conversion using the channel-length-modulation effect. The sensitivity of the sensor adapts automatically to the signal level, so that a dynamic range of six decades is reachable. The process of the conversion does not involve any current integration. No multiple clocks are required in the operation. The circuit does not involve any linear devices. The circuit can be, therefore, implemented densely in silicon using a single-poly technology. Moreover, the development of deep-sub-micron technology favors the design and implementation of the sensor circuit.