Radiation Tolerance of RHBD techniques on a SiGe BiCMOS 350 nm ASIC technology

This work presents the radiation tolerance of a Warm Frond-End Electronics subsystem (WFEE), using Radiation Hardening By Design (RHBD) techniques based on a SiGe BiCMOS 350 nm ASIC technology. The subsystem is in the context of a developing X-Ray space observatory of ESA, named ATHENA, planned to operate in a halo orbit around the second Lagrangian point (L2 Sun - Earth) with 5-year lifetime at the end of the next decade. The WFEE is a mixed electronic system, including analog devices, such as low noise amplifier and current sources for amplifying and biasing cryogenic stages, and also integrating digital devices: serial decoders RS485/ I2C for configuring the current sources. Because of extreme radiation space environment, different RHBD techniques have been used to improve the radiation tolerance of the WFEE electronics. The tolerance against radiation effects TID and SEL have been assessed. The evolution of the main parameters of the amplifier (gain and noise) and of the current sources (output current and noise) with respect to different dose levels has also been measured. The measurements after irradiations show that the RHBD techniques are very effective for improving radiation hardening capabilities of electronic circuits based on this technology.