Four-channel readout ASIC for silicon pad detectors

A custom front-end readout ASIC has been designed for silicon calorimeters supposed to be used in high-energy physics experiments. The ASIC was produced using BJT-JFET technology. It contains four channels of a fast low-noise charge-sensitive preamplifier (CSP) with inverting outputs summed by a linear adder (LA) followed by an RC-CR shaping amplifier (SA) with 30 ns peaking time. Availability of separate outputs of the CSPs and the LA makes it possible to join any number of silicon detector layers to obtain the longitudinal and transversal resolution required using only this ASIC in any silicon calorimeter minitower configuration. Noise performance is ENC=1800e−+18e−/pF at 30 ns peaking time for detector capacitance up to Cd=400 pF. Rise time is 8 ns at input capacitance Cd=100 pF. Power dissipation is less than 50 mW/ chip at voltage supply 5 V.