Radiation tolerance in foundation IPs

Radiation-tolerant variant of Foundation IPs are available various technology nodes, without requiring any change to the underlying manufacturing process. Radiation tolerance characteristics include:
  • Total ionization dose (TID) tolerance of 100 kRad(Si), 300 kRad(Si) or higher
  • SEL immune with threshold LET > 90 MeV-cm2/mg.
  • Static SEU rate < 10-9 #/bit/day in GEO orbit environment.
  • Specialized standard cells
  • DICE flip-flops, with optional delay-filtering for enhanced SET tolerance
  • Clock buffer with reduced SET sensitivity
  • Majority voter for TMR design
  • Hardened memory
  • DICE and non-DICE SRAM bit-cells
  • Built-in logic redundancy
  • Error detection and correction (EDAC)

Radiation tolerance designs are verified with our physics-based SEE analysis methodology. Extensive simulations have been performed at our computing cluster to optimize the layout of circuit cells for SEL immunity and cross-section minimization. Through many design-simulate iterations, hardness is achieved without incurring excessive over-design.

dice_cgd_sim_model

Fig. 1 TCAD model of a DICE flipflop used for validating the SEU-hardness of the design.

dice_cgd_wave1

Fig. 2 TCAD simulated voltage waveform of the storage nodes in a DICE flipflop, showing prompt recovery after hit by a heavy ion.

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