The image sensor is an important part of the digital camera. Depending on the components, they can be classified into two major categories: CCD (Charge Coupled Device) and CMOS (Complementary Metal-Oxide SEMICONDUCTOR).

Image sensors belong to the optoelectronic components in the optoelectronics industry. With the rapid development of digital technologies, semiconductor manufacturing technologies, and networks, the market and the industry are currently facing the arrival of a large integration era of video, audio, and communications across platforms. The beauty of the future of human daily life. For its application in daily life, it is undoubtedly a digital camera product, and its development speed can be described with each passing day. In a few short years, digital cameras have grown from hundreds of thousands of pixels to 400, 5 million pixels or even higher. Not only in developed European and American countries, digital cameras have occupied a large market, and in the developing China, the digital camera market is also growing at an alarming rate. Therefore, its key component, the image sensor product, becomes the current As well as the future industry’s focus, it attracts many manufacturers.

With the rise of all kinds of consumer electronics, the image sensor of surveillance cameras has become one of the most dazzling star products in the semiconductor industry. In image sensors, CCD sensors and emerging CMOS Sensors have gradually found their own application market. Become the mainstream technology in the market. Compared with the CCD sensor, the image sensor of the monitoring camera has the disadvantages of low sensitivity and high signal-to-noise ratio, but it still has the advantages of low power consumption and low cost.

Imaging process CCD and CMOS use the same photosensitive material, so the basic principle of electron generation after receiving light is the same, but the reading process is different: CCD is transferred in frame or line mode with the synchronization signal and clock signal, the whole circuit is very complicated , The read rate is slow; CMOS reads out the signal in the way like DRAM, the circuit is simple, the reading rate is high.

The degree of integration of CCD readout circuits using special manufacturing processes is complex, it is difficult to integrate A/D conversion, signal processing, automatic gain control, precision amplification, and memory functions on a single chip, typically requiring multiple chip combinations to be implemented. A multi-channel non-standard supply voltage is required. With large-scale integrated manufacturing processes, CMOS image sensors can easily integrate the above functions into a single chip. Most CMOS image sensors have both analog and digital output signals.