A Radiation Hardened by Design Cmos Asic for Thermopile Readouts

Introduction: A radiation hardened by design (RHBD) mixed-signal application specific integrated circuit (ASIC) has been designed for a thermopile readout for operation in the harsh Jovian orbital environment. The multi-channel digitizer (MCD) ASIC (shown in Figure 1) includes 18 low noise amplifier channels which have tunable gain/filtering coefficients, a 16-bit sigma-delta analog-digital converter (SDADC) and an on-chip controller. The 18 channels, SDADC and controller were designed to operate with immunity to single event latchup (SE1.) and to at least 10 Mrad total ionizing dose (TID). The ASIC also contains a radiation tolerant 16-bit 20 MHz Nyquist ADC for general purpose instrumentation digitizer needs. The ASIC is currently undergoing fabrication in a commer~ cial 180 nm CMOS process. Although this ASIC was designed specifically for the harsh radiation environment of the NASA led lEO mission it is suitable for integration into instrumentation payloads 011 the ESA JUICE mission where the radiation hardness require~ ments are slightly less stringent.