A comparison of the effects of X-ray and proton irradiation on the performance of SiGe precision voltage references

Laleh Najafizadeh, Akil K. Sutton, Ryan M. Diestelhorst, Marco Bellini, Bongim Jun, John D. Cressler, Paul W. Marshall, Cheryl J. Marshall

Research output: Contribution to journalArticlepeer-review

13 Scopus citations


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.

Original languageEnglish (US)
Pages (from-to)2238-2244
Number of pages7
JournalIEEE Transactions on Nuclear Science
Issue number6
StatePublished - Dec 2007
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Nuclear and High Energy Physics
  • Nuclear Energy and Engineering
  • Electrical and Electronic Engineering


  • Bicmos analog integrated circuits
  • Heterojuction bipolar transistors
  • Ionization damage
  • Proton radiation effects
  • SiGe
  • SiGe HBTs
  • X-rays


Dive into the research topics of 'A comparison of the effects of X-ray and proton irradiation on the performance of SiGe precision voltage references'. Together they form a unique fingerprint.

Cite this