公开(公告)号：US09380208B1

公开(公告)日：2016-06-28

申请号：US14685151

申请日：2015-04-13

Applicant: OMNIVISION TECHNOLOGIES, INC.

Inventor： Bi Yuan ,  Quifeng Jin ,  Liping Deng ,  Liang Zuo

IPC: H04N5/232 ,  H04N5/357 ,  H04N5/378 ,  H04N5/374

CPC classification number: H04N5/23241 ,  H04N5/357 ,  H04N5/3577 ,  H04N5/378

Abstract: A ramp generator includes a supply voltage sampling circuit coupled to sample a black signal supply voltage during a black signal readout, and an image signal supply voltage of the pixel cell during an image signal readout of a pixel cell. A first integrator circuit receives a buffered reference voltage, and an output of the supply voltage sampling circuit. First and second switches are coupled between the first integrator circuit and a first capacitor to transfer a signal representative of a difference between the image signal supply voltage and the black signal supply voltage to the first capacitor. A second integrator circuit is coupled to the first capacitor to generate an output ramp signal coupled to be received by an analog to digital converter. A starting value of the output ramp signal is adjusted in response to the difference between the image signal and the black signal supply voltage.

Abstract translation: 斜坡发生器包括在黑色信号读出期间耦合以对黑色信号电源电压进行采样的电源电压采样电路，以及在像素单元的图像信号读出期间像素单元的图像信号供应电压。 第一积分器电路接收缓冲的参考电压和电源电压采样电路的输出。 第一和第二开关耦合在第一积分器电路和第一电容器之间，以将表示图像信号电源电压和黑色信号电源电压之间的差异的信号传送到第一电容器。 第二积分器电路耦合到第一电容器以产生耦合以由模数转换器接收的输出斜坡信号。 响应于图像信号和黑色信号电源电压之间的差异来调整输出斜坡信号的起始值。