Monolithic JFET preamplifier with nonresistive charge reset

This paper shows how a monolithic JFET preamplifier for spectrometry applications can be upgraded by introducing a nonresistive reset. It was found that the charge reset which employs a forward-biased gate-to-source junction of the input JFET suits this case best. The introduction of the nonresistive feedback is important in two respects. First, it puts into better evidence the intrinsic noise limitations of the monolithic preamplifier. Second, it opens up a new perspective in the design of monolithic preamplifiers for very high-resolution X-ray applications.