CMOS Analog Front End Design for Particle Energy Measurement in Space Environment
Résumé
In situ studies of the geospace environment, including space weather monitoring, is mainly based on the measurements of particles and fields. The particle content of the Earth’s magnetosphere is studied with electron and ion detectors in various energy ranges, from the cold and dense eV solar wind to the MeV radiation belts. Here, the in situ high-energy (50 keV to 725keV) electron measurement is targeted. The design and development of space embedded electronic equipment require a specific approach . An Analog-Front-End (AFE) design methodology is proposed to optimize
noise, bandwidth, consumption, crosstalk and radiation hardness performances of such AFEs for Si semiconductor detectors. The conception of
an Analog-Front-End optimized in noise, band width, consumption, crosstalk and radiation hardness, dedicated to a silicon (SiA) detector. Each channel includes an 8 bits successive approximation register (SAR) ADC in order to digitize the incident electron energy. The chip was designed in a
0.35 μm HV CMOS process. The ASIC measurements have shown that for a charge range of 0.6 fC to 32 fC , the charge - to - voltage conversion gain
is approximately 60 mV/fC. The equivalent noise charge (ENC) is 3119 e- for 40pF input parasitic capacitance while consuming 2.5 mW. The circuit
can perform measurements up to a 650 kHz rate. The next step is to characterize the ASIC associated with the SC detector in a vacuum chamber. Furthermore, the total ionisation dose (TID) and the single event effect ( SEE ) tolerances must also be evaluated