Isolating Micro-Machined Die Packaging Stress during Automated Thermal Calibration
Automated thermal calibration must isolate packaging thermo-mechanical stress shifts from intrinsic silicon sensor signals using real-time compensation.
ISO 26262 Residual Error
Diagnostic Metric
Undetected faults in safety-related systems represent the fraction of dangerous failures that internal diagnostics fail to identify. The iso 26262 residual error quantifies the probability of a violation of a safety goal caused by these hidden malfunctions. It sits at the core of the probabilistic metric for hardware failures.
Calculation Method
Assessment of this value requires a failure mode and effects analysis to determine the diagnostic coverage of every hardware component. Each failure rate is multiplied by the percentage of the fault that remains unobserved by the system monitors. The sum of these individual values provides the total exposure to hazardous events that could occur without warning.
Integrity Target
Integrity levels assigned to the system determine the maximum allowable rate for these undetected malfunctions. An automotive safety integrity level d requires the lowest possible iso 26262 residual error to minimize risk. Meeting these targets involves adding redundant monitoring circuits or increasing the frequency of self-test routines.
Safety Evidence
Safety manuals document the assumptions and the data sources used to derive the failure rates for each transistor or interconnect. Designers verify the accuracy of the diagnostic coverage through fault injection testing where they deliberately introduce errors to see if the system reacts. This proof ensures the hardware design provides the necessary protection against random electronic failures.