Worst-case analysis (WCA) encompasses mechanical dimensional stack-up, and modeling thermal extremes. When applied to electronic circuit design, it establishes the certainty the circuit will function when the characteristics of the base components vary. All components have initial tolerances around their nominal value; this variance widens over time and with temperature changes.
Worst-case circuit analysis is also used to ensure that properties which cannot be measured, such as internal component heating, stay within acceptable limits for component survival. WCA addresses any limitation that cannot be determined from testing alone. When performed early in the design cycle, WCA eliminates design iterations. The characteristics of system sensors and actuators can be included in the analysis to help ensure success with the application.
During the design of M670, extensive WCA ensured each output driver would not overheat internally when:
(1) Subjected to the maximum ambient temperature
(2) Other ECU components were dissipating power
(3) Driving the rated current
(4) Pulsing at the maximum frequency and worst-case duty cycle
(5) When driver components nave weakest allowable characteristics
This assessment would not be possible any other way. The same rigor is applied to all hardware design.