This paper presents architecture and simulation results of the analog part of a multichannel integrated circuit (IC) for optical radiation sensors (visible and infrared light) that can be used in high-speed applications. The complete prototype, called Optical Radiation Readout Circuit (ORRC) is composed of analog front end and moderate-resolution analog-to-digital converter (ADC) included in every channel. This paper is focused on fast analog signal processing taking into account parameters such as pulse shaping, noise performance, and stability issues. The front-end part of the proposed IC is composed of a Charge Sensitive Amplifier (CSA) and an active filter (called shaper). The main design challenges related to high-repetition-rate signal processing are discussed in detail. The topology of the circuit is verified with a number of simulations including Monte Carlo sessions.