Major differences between CCD and CMOS

Many netizens have asked about the main difference between CCD and CMOS. For the time being, let's take a look at the two different types of image photosensitive elements with the same function through a simple comparison.
Both CCD and CMOS basically convert light to electricity using the silicon photodiode. The principle of this conversion is similar to the "Solar Cell" effect of the "Solar Energy" electronic computer in your hands. The stronger the light, the stronger the power. On the contrary, the weaker the light and the weaker the power, the light image is converted into an electronic digital signal.
Compare the structure of CCD and CMOS, and the location and quantity of ADC are the biggest difference. To put it simply, follow the content we mentioned in the previous section "Working Principle of CCD photosensitive elements (I. Each time the CCD is exposed, pixel transfer is performed after the shutter is closed, and the charge signals of each pixel (pixel) in each row are sequentially transferred to the buffer, the bottom line leads the output to the amplifier next to the CCD for amplification, and then Concatenates the ADC output; relatively, in the CMOS Design, each pixel is directly connected to the ADC (amplification and analog digital signal converter), and the signal is directly amplified and converted to a digital signal.

Comparison of advantages and disadvantages
CCD CMOS
Design a single optical sensor connection Amplifier
The high-sensitivity opening is small and the sensitivity is low in the same area.
High Cost line quality impact, high cost CMOS integration, Low Cost
Low Resolution connection complexity, high resolution, and High Technology
Noise Ratio: single amplification; Low Noise: 1 million; high noise
Power consumption is directly amplified with high power consumption and low power consumption.
Due to the basic differences in construction, we can list the performance differences between the two. CCD is designed to ensure that the signal is not distorted during transmission (the exclusive Channel is designed), and the data integrity can be maintained by aggregating each pixel to a single amplifier; the CMOS process is relatively simple and there is no exclusive Channel Design. Therefore, you must first zoom in and then integrate the data of each pixel.
In general, the applications of CCD and CMOS are reflected in the imaging effect, which includes ISO sensitivity, manufacturing cost, resolution, noise and power consumption. Different types of differences:
ISO sensitivity difference: Since each CMOS pixel contains an amplifier and A/D conversion circuit, excessive additional devices compress the surface area of a single pixel's photosensitive area, so under the same pixel, in the same size, the sensitivity of CMOS is lower than that of CCD.
Cost Difference: CMOS is applicable to Mos processes commonly used in the semiconductor industry. All peripheral facilities can be integrated in a single chip at a time to save the cost and yield loss required for wafer processing; in contrast, CCD outputs information by means of Charge Transfer, and must establish another transmission channel. If a pixel fault (fail) exists in the channel, it will lead to congestion of a whole line of signals and cannot be transmitted, therefore, the yield of CCD is lower than that of CMOS, and the manufacturing cost of CCD is higher than that of CMOS in addition to the peripheral areas such as the transmission channel and ADCs.
Resolution difference: in the first "sensitivity difference", because the structure of each CMOS pixel is more complex than that of CCD, its photosensitive opening is less big than that of CCD, compared with CCD and CMOS Sensors of the same size, the resolution of CCD sensors is usually better than that of CMOS. However, if the size limit is exceeded, the original CMOS photosensitive device in the industry can now reach 14 million pixels/full width, the advantage of CMOS technology in terms of the volume rate can overcome the difficulties in manufacturing large-sized photosensitive originals, especially the size of the full-width 24mm-by- 36mm.
Noise difference: because each CMOS sensor is paired with an ADC amplifier, if measured in millions of pixels, more than one million ADC amplifiers are needed, although they are products under unified manufacturing, however, each amplifier is more or less slightly different, and it is difficult to achieve the effect of amplification and synchronization. Compared with CCD of a single amplifier, CMOS will eventually calculate more noise.
Power Consumption difference: the charge driving mode of CMOS images is active, and the electric charge produced by the photosensitive diode is directly amplified by the crystal next to it, but the CCD is passive, the extra voltage is required to move the charge in each pixel to the transmission channel. This additional voltage usually requires a level above 12 volts (V). Therefore, CCD must have more precise power supply line design and withstand voltage strength, high driving voltage makes the power of CCD much higher than that of CMOS.
Although CCD is superior to CMOS in image quality and other aspects, it is undeniable that CMOS features low cost, low power consumption, and high integration. Due to the enthusiastic demand for digital imaging, the low-cost and stable supply of CMOS has become a favorite of manufacturers. Therefore, its manufacturing technology is constantly improved and updated, gradually narrowing the gap between CCD and CMOS. The new-generation CCD is aimed at reducing power consumption, with a view to entering the Mobile Phone mobile phone, and the CMOS series begins to integrate large area and High-Speed Image Processing Chips, through subsequent image processing, we can correct the noise and image quality, especially the success of the Canon series EOS d30 and EOS 300D, the high-speed image processing chip can be used to shorten the processing time and capability of High-pixel CMOS images. In addition, the wide-size full-range uses Kodak DCS pro14n, DCS Pro/N, and DCS Pro/C as the call for a series of digital devices. In the future, CMOS will provide high-end image market products with a promising future.