When designing temperature sensing/compensation circuitry, NTC or linear PTC thermistors are most often included in a voltage divider with fixed resistors. The two circuits shown above are typical examples of how thermistor/resistor networks can be used. Circuit A shows a typical microprocessor-based application that reads out temperature using a linearized voltage input from a thermistor /resistor network. With this temperature reading, the system can perform a variety of functions such as shutting down, increasing or decreasing power levels, turning on a fan, or even simply displaying the temperature point. Circuit B shows a way to correct the contrast voltage of an LCD operating over a wide range of temperature. Such LCDs lose contrast as temperature increases. The addition of the thermistor/resistor compensation network is meant to control the contrast level by increasing the LCD drive voltage to maintain a clear, consistent display. The same principles just described for microprocessor temperature control and LCD compensation can be applied for other similar applications including those listed. With this tool, the user has the ability to input the required voltage variation in function of the temperature. The tool will then compute the most appropriate thermistor/resistor network along with providing VISHAY part numbers.