The Definition of Low Niose Amplifier

The Definition of Low Niose Amplifier_Manufacturer of Thermistors, Laser drivers, Resistor kits, Smt capcitor kits & Tec controllers

As it is known to all, some very low frequency noise (0.1Hz to 10Hz) can’t be measured by oscilloscope, so we design a circuit to amplify these low noises to make sure noise value can be common figures which has been given in amplifier datasheets. As this circuit designed to amplify the low frequency noise, we achieve this function ranging from a 0.1Hz second order high pass filter to a 10Hz forth order low pass filter. As the internal noise of amplifier will also influence the testing result, we will try to reduce itself noise coefficient to improve the output ratio of signal power vs. noise power.

Ideal amplifier noise coefficient is F = 1 (0 db), and its physical meaning is that the output ratio of signal power vs. noise power is equal to the input ratio of signal power vs. noise power. A well-designed low noise amplifier FN can reach < 3 db. When testing low noise figure, use temperature (Te) as amplifier noise performance metrics: Te = T0 (F – 1). Here, unit of noise coefficient and noise temperature are both kelvin (K) when it is under ambient temperature.

The signal that circuit received is very weak, so the low noise amplifier has to achieve the function of amplifying small signal. Besides, due to the influence of strong signal interference in the transmission path, the strength of the noise will change also. Therefore, the amplifier needs to have a large enough linear range and gain can be adjusted..For more information, please visit our website:http://www.analogtechnologies.com/thermistor.html