Development of front-end electronics for the luminosity detector at ILC

The design and measurements of the prototype front-end electronics for the luminosity detector (LumiCal) at International Linear Collider (ILC) are presented. The challenges of the LumiCal front-end are pointed out and the proposed architecture comprising switched-gain preamplifier, pole-zero cancellation circuit (PZC) and switched-gain shaper is described. The preamplifier works for a wide range of input capacitance values reaching more than 100 pF. The input charge dynamic range is 0.4 fC – 10 pC and covers more than 4 orders of magnitude. The circuit has to be fast with a peaking time (T
peak
) of about 70 ns. The prototype ASIC including 8 channels was designed and produced in 0.35 μm CMOS technology. The results of measurements on gain, noise, input pulse rate and crosstalk are presented.