A high-speed low-noise front-end ASIC prototype for ionization chambers of high-intensity beam monitoring

We present the design and test results of a high-speed low-noise front-end readout Application Specific Integrated Circuit (ASIC) prototype, which is designed for a novel ionization chamber of the high intensity beam detection. This ASIC prototype is a single-channel ASIC and composed of a charge collection electrode, a Charge Sensitive Amplifier (CSA), a discriminator, a buffer and a two-stage source follower. Three different feedback capacitances are implemented in the CSA. The prototype has been manufactured in a standard 0.18μm CMOS process. The test results show that the input equivalent noise is from 22.8 e- to 30.6 e-. The input charge range is about 1.18 fC with a non-linearity of 3.13%, 3.95 fC with a non-linearity of 2.38% and 7.58 fC with a non-linearity of 3.42% for the feedback capacitance of 5 fF, 30 fF and 60 fF, respectively. The shaping time of the CSA can be less than 0.5μs. The power consumption of the CSA and the whole ASIC prototype is about 108 μW and 1.179 mW under the power supply of 1.8 V, respectively.