一种适用于16级TDI CMOS图像传感器的电流型累加器(英文)

A Current-mode Accumulator for 16-Stage TDI CMOS Image Sensors

提出一种适用于混合域累加的16级时间延迟积分(Time Delay Integration,TDI)型CMOS图像传感器的电流型累加器.为了实现混合域的累加,电流信号首先在电流型累加器中累加4次,累加的结果被量化成数字量后再次完成4次的累加,即4×4的混合累加模式.详细分析了电流型累加器的热噪声和闪烁噪声特性,并给出了等效输入噪声的均方根电压表达式,并结合仿真工具进行分析验证.提出的电流型累加器电路在CMOS180nm 1.8V供电电源的工艺下实现,电路的功耗为0.37mW,芯片面积为0.03mm×0.82mm.经过电流型累加器的4次累加后,能够将信号的信噪比提升5.86dB.

A current-mode accumulator used in mixed analog and digital domain for 16-stage TDI CMOS image sensor is presented.The signal current is used instead of signal voltage as the information carrier to realize accumulation.The current signals are accumulated 4times and then converted to digital signals to accomplish the other accumulation by 4times, i e, 4×4accumulation mode.Both thermal noise and flicker noise are analyzed and the expressions of the input-referred root mean square（ RMS） noise are given.The accumulator was postsimulated using 1P4M0.18 μ m CMOS process technology.The power consumption is 0.37mW at 1.8Vsupply, and the area is 0.03mm×0.82mm.The signal-to-noise ratio（ SNR） can be enhanced 5.86dB by the current-mode accumulator.