Question
My question has to do with the EXT VSET connector on the WTC3243. How is the voltage I apply to the EXT VSET related to the temperature setting? What is the relationship between this applied voltage and the temperature that will result as the set value? I cannot find a transfer function in the manual.
Answer
The transfer function is not specified in the documentation because our controllers are universal. They control using almost any temperature sensor, so the transfer function depends specifically on the sensor.
For example, if you use a 10 kΩ thermistor (follow this link for a 10 kΩ example Resistance vs. Temperature chart) and the 100 µA bias current, the voltage at 25°C will be 1 V.
For a 20 kΩ thermistor (20 kΩ example chart) with the same bias current, the voltage at 25°C will be 2 V.
If you let us know what sensor you’ll be using, we can also help determine the voltage-to-temperature relationship.