Multi-Channel Low-Noise Analog Front Design

With the development of digital nuclear pulse processing technology, the requirements for the analog front-end circuit of digital energy spectrometers are getting higher and higher. Not only need to reduce the noise caused by the device as much as possible, but also need to meet the needs of multi-channel data acquisition. This article based on VGA (Variable Gain Amplifier) has designed a multi-channel low-noise analog front-end circuit to meet the functional requirements of the energy spectrometer while reducing the signal transmission in the analog front-end circuit as much as possible. The circuit noise is strictly controlled to ensure the signal-to-noise ratio of signal transmission. AD9255 is used for waveform digitization, and the input range is 100 μV-2 VPP. After testing, the circuit has a wider gain range and better noise control. Input 100 μVpp signal when the analog front-end gain is 24 dB, and its signal-to-noise ratio can reach 1:1.