MS120: Operating temperature ratings

The maximum allowable operating temperature of the board is governed by several factors.To determine the highest permissible operating temperature you need to evaluate each factor separately and then use the worst (lowest temperature) answer.

The factors that must be taken into account are:

1. The LCD, if you are using one, has a maximum operating temperature of 50°C and storage temperature of 60°C. Please contact us for extended temperature range displays (special order).
2. The semiconductors on the board have a maximum ambient temperature rating of 70°C.
3. The 5V power supply regulator will shut down and self-protect if its junction temperature exceeds 150°C. How hot it actually gets depends heavily on the supply voltage.

   The 5V regulator can operate at 70°C ambient for all conditions of loading, including 3mA for the optional LCD and 15mA for the SPice connectors, at supply voltages up to 18V. Above 18V you need to derate the upper temperature limit as shown under power supply details.

4. The chip driving the outputs will also self-heat, and eventually fail if run too hot for too long. Evaluating this factor is discussed under MS120 External digital outputs
5. Hot components fail faster than cool components. For semiconductors, lowering the temperature by 10°C doubles the life time.

The minimum operating temperature is -40°C with the proviso that there be no water condensation. Conformally coated boards can be supplied to special order to minimize the effects of condensation.