A 0.8-V 4096-Pixel CMOS Sense-and-Stimulus Imager for Retinal Prosthesis
A 0.8-V 4096-Pixel CMOS Sense-and-Stimulus Imager for Retinal Prosthesis
复制标题
用于视网膜假体的 0.8V 4096 像素 CMOS 传感和刺激成像器
DOI：
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发表时间：
2013
影响因子：
3.1
通讯作者：
C. Hsieh
中科院分区：
文献类型：
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作者：
Chih;C. Hsieh
本文介绍了一种用于视网膜假体的0.8 v、4096像素、集成感觉刺激（SAS）功能的CMOS成像仪。该像素由一个光子-双相电流转换器（传感器）和一个平衡电流模式刺激器（刺激器）组成，以实现高集成和低功耗的高分辨率视觉恢复解决方案。为了各种目的，实现了测试模式、编程（PG）模式和植入（IP）模式三种操作模式。在测试模式下，内部信号串行多路输出用于芯片验证。在PG模式下，电流刺激器阵列的输出模式通过外部地址可编程，用于视网膜的图案化电刺激实验。在IP模式下，芯片功能齐全，输入/输出数量最少，为体内操作优化了4个。采用台积电（TSMC） 0.18 μm CMOS图像传感器技术，设计制作了64 × 64 sas像素阵列、30 × 30 × μm2像素尺寸、33.3%填充系数的原型芯片。所提出的芯片可以在0.8到1.8 V的宽电源范围下工作。测量到的转换增益和最大双相电流幅值分别为144 nA/lx （1.8 V）、21 nA/lx （0.8 V）、±50 μA （1.8 V）和±10 μA （0.8 V）。提出的SAS CMOS成像仪为人工视网膜提供了一个集成的SAS解决方案，其最高阵列分辨率为4096像素，在12.5 ft/s下功耗为0.18 mW，在300 lx照明下电源为0.8 v。
This paper presents a 0.8-V CMOS imager with 4096 pixels and an integrated sense-and-stimulus (SAS) function for retinal prosthesis. The pixel consists of a photon-to-biphasic-current converter (sense) and a balanced current-mode stimulator (stimulus) to achieve a highly integrated and low-power solution for high-resolution vision recovery. Three operation modes, that is, test mode, programming (PG) mode, and implanted (IP) mode, have been implemented for various purposes. In test mode, the internal signals are multiplexed out serially for chip verification. In PG mode, the output pattern of the current stimulator array is programmable by external addresses for patterned electrical stimulus experiments of retina. In IP mode, the chip is fully functional with a minimized number of input/output as four optimized for in vivo operation. A prototype chip with a 64 × 64 SAS-pixel array, a 30 × 30 × μm2 pixel size, and a 33.3% fill factor was designed and fabricated in Taiwan Semiconductor Manufacturing Company (TSMC) 0.18- μm CMOS image sensor technology. The proposed chip was operational under a wide supply range from 0.8 to 1.8 V. The measured conversion gains and maximal biphasic current amplitudes are 144 nA/lx (1.8 V), 21 nA/lx (0.8 V), ± 50 & μA (1.8 V), and ±10 & μA (0.8 V), respectively. The proposed SAS CMOS imager presents an integrated SAS solution for artificial retina with the highest array resolution of 4096 pixels and a low power consumption of 0.18 mW at 12.5 ft/s and a 0.8-V supply under 300-lx illumination.