What’s the purpose of a preamplifier?
In small signals measurement, preamplifiers are used to improve the signal-to-noise ratio (SNR). This is especially important in sensory based measurements where signals are easily affected by noise. The preamplifier is used to amplify the signal. Preamplifiers are sometimes used to change the output impedance of sensors as well.
Choosing an appropriate preamplifier based on the application is the key to achieving better quality measurement of signals from sensors.
Different types of preamplifiers
The choice of preamplifier is usually determined by the type of sensors being used and obviously the application. Some sensors provide voltage outputs while others, such as photodiodes, may provide current outputs. In some cases, fast response time and/or low noise are critical. Factors to consider when choosing a preamplifier include:
- Current or Voltage input?
- AC or DC Coupling?
- Frequency Bandwidth
- Input Impedance
- Differential or Unbalanced input?
NF are leaders in very small signal measurements and therefore amplification. They produce a large range of both ultra low noise voltage-input and current-input preamplifiers with varying gain and frequency response making them suitable for different applications. In addition, NF have a range of complementary products and accessories to suit; Such as Low noise DC power supplies, Frequency Response Analyzers and Lock-in amplifiers.
Based on an article first published by NF and is intended for general information only