TID and Heavy-Ion Performance of an RHBD Multichannel Digitizer in 180-nm CMOS

Abstract

We present the design, fabrication, and radiation testing of a custom 20-channel application-specific integrated circuit (ASIC) for amplification and digitization of microvolt signal levels from space instrumentation (e.g., thermopile sensors) operating in harsh space radiation environments. The ASIC is fabricated in a commercial 180-nm complementary metal oxide silicon (CMOS) process node using a combination of radiation hard by design and discrete-time analog signal processing to mitigate leakage, offset, 1/ f, and thermal noise. The chip has an input-referred integrated noise voltage of 190 nV in a 240-Hz bandwidth. Irradiation with very high total ionizing dose (TID) and high-energy heavy ions was carried out to evaluate the chip's radiation hardness. The chip's postradiation performance evidenced parametric immunity to greater than 50 Mrad (Si) TID and no single-event latch-up up to at least 123.6 MeV-cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> /mg linear energy transfer.