Semiconductor device

Abstract

The present invention makes it possible to read a pixel signal at high speed. A pixel array includes a plurality of pixels that store an electrical charge. The amount of stored electrical charge is based on the amount of received light. A first pixel current source and a second pixel current source are coupled in parallel between a ground voltage and a pixel output node on a pixel signal read line. A switch is disposed in a wiring path that couples the pixel output node, the second pixel current source, and the ground voltage.

1 . (canceled) 
     
     
         2 . A semiconductor device comprising:
 a pixel array having a plurality of pixels that store an electrical charge based on the amount of received light, the pixels each including:   a photoelectric conversion element that stores the electrical charge based on the amount of received light;   a diffusion section that generates a voltage corresponding to the electrical charge stored in the photoelectric conversion element;   a transfer transistor that transfers the electrical charge stored in the photoelectric conversion element to the diffusion section; and   an amplifying transistor that has a gate coupled to the diffusion section, a drain coupled to a power supply voltage line, and a source;   a pixel signal read line that is coupled to the pixels;   a pixel current source that is disposed between a ground voltage and a pixel output node on the pixel signal read line; and   a detection block that is disposed between a power supply voltage and a detection node coupled to the drain of the amplifying transistor through the power supply voltage line;   wherein the detection circuit outputs an output signal according to the voltage of the detection node and the output signal from the detection block is input to a control electrode of the pixel current source.   
     
     
         3 . The semiconductor device according to  claim 2 , wherein the detection circuit includes:
 a diode element that is disposed between the power supply voltage and the detection node coupled to the drain of the amplifying transistor through the power supply voltage line; and   an amplifier that amplifies the difference between a reference voltage and the voltage of the detection node.   
     
     
         4 . The semiconductor device according to  claim 3 ,
 wherein the diode element formed of a sufficiently large element is disposed with respect to the amplifying transistor.