Sensor circuit

摘要

A method of measuring signals related to a photodiode based sensor and calculating a corrected data value thereof is disclosed. A nominal reset voltage value of the photodiode may be measured. A knee point voltage may be applied to the photodiode and resets a voltage on the photodiode to the knee point voltage when the voltage on the photodiode falls below the knee point voltage. Applying the knee point voltage may extend the dynamic range of the sensor. An output voltage of the photodiode at end of an integration time of the photodiode may be measured. The knee point voltage may be applied again after the end of the integration time. A voltage value of the photodiode of the knee point voltage may be measured. The nominal reset voltage value, the output voltage of a sensor and the knee point voltage may be reported to calculate the corrected data value.

主权项

1. A method for adjusting a pixel voltage, comprising:
applying a first voltage to a photodiode and to a floating diffusion capacitance after an integration period, the first voltage sufficient to substantially fill the photodiode with electrons; applying a second voltage to the photodiode after applying the first voltage and after the integration period; and reading a voltage of a photodiode after applying the second voltage by: resetting the floating diffusion capacitance; transferring the voltage of the photodiode to the floating diffusion capacitance; and transferring the voltage of the floating diffusion capacitance to an output node, wherein the voltage of the floating diffusion capacitance serves as a knee point voltage.