Difference between CCD sensor and CMOS sensor

Noise: Since each photodiode in CMOS needs to be equipped with an amplifier, if it is measured in megapixels, then more than one million amplifiers are needed, and the amplifier is an analog circuit, it is difficult to keep the results obtained by each amplifier consistent Therefore, compared with a CCD sensor with only one amplifier placed on the edge of the chip, the noise of the CMOS sensor will increase a lot, affecting the image quality.

Power consumption: The image acquisition method of the CMOS sensor is active, and the charge generated by the photodiode will be directly amplified by the transistors next to it; while the CCD sensor is passively collected, a voltage must be applied to move the charge in each pixel Transmission channel. The applied voltage usually needs 12 ~ 18V, so CCD must also have more precise power line design and withstand voltage strength, high driving voltage makes the power consumption of CCD is much higher than that of CMOS. The power consumption of CMOS is only 1 of CCD ／ 8 to 1/10.

Cost: Since the CMOS sensor uses the most commonly used CMOS process for general semiconductor circuits, peripheral circuits (such as AGC, CDS, Timinggenerator or DSP, etc.) can be easily integrated into the sensor chip, so the cost of the peripheral chip can be saved; CCD uses charge The data is transmitted by means of transmission. As long as one of the pixels cannot be operated, it will cause a whole row of data to be unable to be transmitted. Therefore, it is much more difficult to control the yield of CCD sensors than CMOS sensors. Even experienced manufacturers are difficult to produce products. The level of 50% will be exceeded within half a year. Therefore, the manufacturing cost of CCD sensors will be higher than that of CMOS sensors.

Prospects of CCD and CMOS sensors CCD is superior to CMOS in terms of image quality, and CMOS has the characteristics of low cost, low power consumption, and high integration. However, with the advancement of CCD and CMOS sensor technology, the difference between the two will be gradually reduced. The new generation of CCD sensors have been improved in power consumption, while the CMOS sensor is insufficient in improving resolution and sensitivity. I believe that the continuous improvement of CCD and CMOS sensors will bring us a better world of digital imaging.