| 摘要 |
Disclosed herein is an active pixel sensor. A first transistor amplifies voltage generated in response to light at an integration node N. A second transistor is a selecting transistor, and performs a function of selecting a specific pixel from a pixel array. A third transistor resets voltage of the integration node N to voltage supplied from VDD during a reset period. A fourth transistor is a photogate, and performs a function of connecting a photogate capacitance to the integration node N, and thus increasing a dynamic range when the voltage of the integration node N is VDD-Vth (photogate: fourth transistor). A fifth transistor is a logarithmic transistor, and performs a function of generating a signal voltage in a logarithmic response to light when the voltage of the integration node N is logarithmic bias voltage-Vth (logarithmic transistor: fifth transistor); and a photodiode performs a function of converting photons into electron pairs in a depletion layer, and then causing signal charges to be accumulated when light is incident from outside.
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