Celsius_temperature_to_frequency_converter

Published:2009/7/20 3:52:00 Author:Jessie | From:SeekIC

Celsius (Fahrenheit) temperature-to-frequency converter. No sensor is required since the AD537 has an internal VTEMP output. The converter output tracks the temperature at a rate of 10 hertz per degree Celsius or Fahrenheit, depending on the resistor-capacitor values chosen. All values in parentheses are for Fahrenheit. To calibrate measure the room temperature in Kelvin. Measure the temperature output at pin 6 at that temperature. Calculate the offset adjustment by dividing the VTEMP at pin 6 in milli volts by the room temperature in Kelvin, then multiplying by 273.2 The offset voltage will be in milli volts. Then disconnect the 49-ohm resistor and adjust the 2K pot for the offset voltage at pin 7. Connect the 49dm resistor. Then adjust the 500-ohm slope trimmer for room temperature, or 25℃, which results in 250 hertz (courtesy Analog Devices, Inc.).



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