A charge sensitive preamplifier made with SiGe bipolar transistors

We have characterized some commercial SiGe bipolar transistors to be used at low injection level and in a wide temperature range, in view of their possible application in experiments with large number of channels. After having observed that they are very suitable for low noise and high-speed applications we have designed and built a charge sensitive preamplifier able to work at tens of nsec shaping time. In this paper, the preamplifier performances at room temperature are described.