Adaptive photoreceptor including adaptive element for long-time- constant continuous adaptation with low offset and insensitivity to light

摘要

An adaptive photoreceptor semiconductor circuit for long-time- constant continuous learning having a low offset and insensitivity to light includes a photodiode in series with an MOS feedback transistor connected across a potential difference. An inverting amplifier comprises a first MOS amplifier transistor having its gate connected to a source of bias voltage potential in series with an cascode transistor having its gate connected to a source of cascode voltage potential and a second MOS amplifier transistor having its gate connected to the common connection between the photodiode and the MOS feedback transistor. An output node comprises the connection between the first MOS amplifier transistor and the cascode transistor. A light insensitive adaptive element has a driven node connected to the output node and an isolated node connected to the gate of the MOS feedback transistor. A capacitive voltage divider is connected between a first power supply rail, the adaptive element, and the output node.