Current-amplifying logarithmic mode CMOS image sensor

摘要

A current-amplifying logarithmic mode CMOS image sensor having a first MOS transistor, a second MOS transistor, a third MOS transistor and a sensing device. The gate terminal and the first connection terminal of the first MOS transistor are tied to a high voltage terminal. The gate terminal of the second MOS transistor and the second connection terminal of the first MOS transistor are tied to a node point. The first connection terminal of the second MOS transistor is tied to the high voltage terminal. The gate terminal of the third MOS transistor is tied to a row select signal. The first connection terminal of the third MOS transistor is tied to the second connection terminal of the second MOS transistor. The second terminal of the third MOS transistor serves as a voltage output terminal. The sensing device includes a PMOS transistor and a lateral bipolar junction transistor. The first connection terminal of the PMOS transistor is connected to the node and the second connection terminal of the PMOS transistor is connected to a grounded terminal. The gate terminal of the PMOS transistor is tied to a terminal for receiving a voltage control signal. The emitter terminal of the lateral PNP bipolar junction transistor is connected to the node point and the collector terminal of the lateral PNP bipolar junction transistor is connected to the ground terminal. The base terminal of the lateral PNP bipolar junction transistor remains in a floating state.