A VLSI front-end circuit for microstrip silicon detectors for medical imaging applications

An analog CMOS-Integrated Circuit has been developed as Front-End for a dou ble-sided microstrip silicon detector. The IC processes and discriminates s ignals in the 5-30 keV energy range. Main features are low noise and precis e timing information. Low noise is achieved by optimizing the cascoded inte grator with the 8 pF detector capacitance and by using an inherently low no ise 1.2 mu m CMOS technology. Timing information is provided by a double di scriminator architecture. The output of the circuit is a digital pulse. The leading edge is determined by a tired threshold discriminator, while the t railing edge is provided by a zero crossing discriminator. In this paper we first describe the architecture of the Front-End chip. We then present the performance of the chip prototype in terms of noise, minimum discriminatio n threshold and time resolution. (C) 1999 Elsevier Science B.V. All rights reserved.