A Comparison of the Effects of X-Ray and Proton Irradiation on the Performance of SiGe Precision Voltage References

Abstract

A comprehensive investigation of the performance dependencies of irradiated SiGe precision voltage reference circuits on 1) total ionizing dose (TID), 2) circuit topology, and 3) radiation source is presented. Two different bandgap voltage references were designed using a first-generation (50-GHz) SiGe BiCMOS technology platform, and subsequently exposed to X-rays at doses of 1080 krad(SiO 2 ) and 5400 krad(SiO 2 ). The degradation in circuit performance following X-ray irradiation depends on both the TID level and the chosen circuit topology. Measurement results show that large TID levels can significantly shift the magnitude of the output voltage. Explanations for the observed shifts are provided by utilizing detailed analyses of the two circuit topologies and considering device-to-circuit interactions. The primary factor responsible for the difference in the circuit response before and after irradiation can be attributed to the excess base leakage current in the SiGe HBT. To investigate the impact of radiation source, the circuit topology showing the worst-case degradation from the X-ray experiment was independently exposed to 63-MeV protons at the same effective TID level. A clear source dependence in the circuit response was observed, and possible origins of this behavior are identified.

Single Event Transient Response of SiGe Voltage References and Its Impact on the Performance of Analog and Mixed-Signal Circuits

“…2 shows the schematic of the voltage regulator designed for this study. An exponential, curvature-compensated BGR [32] was used to provide the reference voltage to the positive input of an operational amplifier (opamp). The opamp is a two-stage amplifier followed by an emitter-follower buffer, and it is biased with an on-chip current source.…”

Low-Power, Subthreshold Reference Circuits for the Space Environment: Evaluated with γ-rays, X-rays, Protons and Heavy Ions

“…Beyond the existing performance requirements of commercial applications, space microelectronics are required to be robust to the increased radiation levels of the space environment [5,[18][19][20][21][22][23][24][25][26][27]. Hence, there is a lot of ongoing research activity to investigate the design of CMOS based analog, digital and mixed-signal, radiation tolerant circuits [28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45], including those that operate in the subthreshold regime [46][47][48].…”

Impact of the non-ideal temperature dependence of IC-VBE on ultra-wide temperature range SiGe HBT bandgap reference circuits

“…Precision bandgap references (BGRs) are extensively used in a wide variety of circuits required for such missions, and have been demonstrated to work well at cryogenic temperatures [2] [3]. To further optimize BGR performance at cryogenic temperatures, it is necessary to understand and model the nonidealities found in existing designs, which we address in this work for the first time.…”

“…In addition, a key question centers of whether we can successfully model BGR performance over extremely-wide temperature ranges using the transistor I C −V BE model of [5]. The first-order BGR design from [2] is used here, which was fabricated using a first-generation SiGe BiCMOS technology with 50 GHz cut-off frequency at room temperature. II.…”

“…II. TECHNICAL APPROACH AND RESULTS Fig.1 shows the schematic of the BGR analyzed [2]. M 4 -M 7 and Q 1 -Q 2 , along with resistor R 1 , generate the PTAT bias current I P T AT , which is set by ΔV BE .…”