2023.05.15
Release time：2022-06-29
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The signals transmitted from the correction sensors are relatively weak. If there is significant noise during sensor operation, it can easily drown out the correction signal, affecting the smooth operation of the entire production process. Therefore, it is essential to pay attention to the noise immunity design in the sensor circuit during the sensor design and manufacturing process. Before dealing with noise interference signal transmission, it is necessary to understand the causes of sensor noise.
Noise during sensor operation is normal, and its main sources include the following:
Low-frequency noise
Discontinuous conductive particles inside the sensor are a major cause of low-frequency noise. This is especially true for some carbon film resistors, which contain many discontinuous small particles. Current passing through these particles is affected by the particles, causing changes in resistance and conductivity, leading to changes in current magnitude, and in some cases, even flash arcing.
Shot noise in semiconductor devices
When the voltage across a semiconductor changes, the amount of charge in its barrier region changes, inducing a capacitance effect. When the applied forward voltage increases, a capacitor-like charging effect occurs, while when the reverse voltage increases, a capacitor-like discharging effect occurs. The above two effects cause slight fluctuations in the current, thus creating current noise.
High-Frequency Thermal Noise
The electrons within the conductor of a polarization correction sensor inherently exhibit random motion. Changes in temperature alter this random motion. As temperature rises, the motion becomes more intense and disordered, becoming a significant noise source within the current. This noise is particularly pronounced in high-frequency circuits.
There are many reasons that can induce noise in sensors. Before designing a polarization correction sensor, it is crucial to fully consider the noise sources mentioned above and minimize their impact on signal transmission to improve efficiency.
Noise during sensor operation is normal, and its main sources include the following:
Low-frequency noise
Discontinuous conductive particles inside the sensor are a major cause of low-frequency noise. This is especially true for some carbon film resistors, which contain many discontinuous small particles. Current passing through these particles is affected by the particles, causing changes in resistance and conductivity, leading to changes in current magnitude, and in some cases, even flash arcing.
Shot noise in semiconductor devices
When the voltage across a semiconductor changes, the amount of charge in its barrier region changes, inducing a capacitance effect. When the applied forward voltage increases, a capacitor-like charging effect occurs, while when the reverse voltage increases, a capacitor-like discharging effect occurs. The above two effects cause slight fluctuations in the current, thus creating current noise.
High-Frequency Thermal Noise
The electrons within the conductor of a polarization correction sensor inherently exhibit random motion. Changes in temperature alter this random motion. As temperature rises, the motion becomes more intense and disordered, becoming a significant noise source within the current. This noise is particularly pronounced in high-frequency circuits.
There are many reasons that can induce noise in sensors. Before designing a polarization correction sensor, it is crucial to fully consider the noise sources mentioned above and minimize their impact on signal transmission to improve efficiency.
