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 the International Linear Collider (ILC) are presented. The challenges of the LumiCal front-end electronics are discussed 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 of up to 100 pF. The input charge dynamic range extends from < 0.4 fC to > 10 pC and covers more than four orders of magnitude. To conform with the timing requirements a peaking time ( T peak ) of about 70 ns was chosen. The prototype ASIC comprising eight channels was designed and fabricated in 0.35 μ m CMOS technology. The results of measurements on gain, noise, high count rate performance and crosstalk are presented.