This LED spotlight example demonstrates the value of simulating both the electrical and thermal aspects of power dissipating circuits together, simultaneously. In this design, a Vishay NTCLE100 Thermistor is used in a detection circuit to monitor the enclosure temperature. It is used for thermal shut-down protection, to keep the enclosure temperature well below the "Tg" (glass transition temperature) of the spotlight's Nylon 6 polymer lens. This is particularly helpful when operating at higher external ambient temperatures.

The thermal side of the circuit consists of connected BCI-ROMs generated by Simcenter Flotherm in the IEEE Standard VHDL-AMS format.  Thermal BCI-ROMs for the linear regulator, three LEDs, and the current sense resistor are connected to electrical models of these devices. The thermal environment is represented by a BCI-ROM of the rest of the system: PCB, lamp casing, and the thermistor.

The ability to include an accurate model of the thermal environment is key to having "thermally-aware" circuit functional design and board layout processes.