TMP01 AD654 Temperature-to-Frequency Converter

This is a TMP01 Temperature-to-Frequency Converter circuit. Converting voltage to the frequency domain is another common method of transmitting analog information. This circuit uses monolithic voltage-to-frequency converters (VFCs) that has some advantages like low cost a robust, and has open-collector digital output. The important information is frequency, so it is immune to voltage drops and noise. The temperature data can be successfully transmitted as long as the conversions between temperature and frequency are done accurately. Here is the schematic diagram of the circuit:

TMP01 Temperature to Frequency Converter circuit schematic diagram
This circuit uses TMP01 and AD654 VFC. AD654 VFC gives a square wave output that is proportional to the dc input voltage. The output of AD654 VFC is determined by following equation:

This temperature to frequency conversion is done by simply connecting the VPTAT output to the input of the AD654. The sensitivity of this circuit is 25 Hz/°C given by the 5 mV/°C temperature coefficient, and centered around 7.5 kHz at 25°C. To calibrate the absolute accuracy of the AD654, the trimming resistor R2 is used. On the receiving end, the AD650 can be used to accurately convert the frequency back to a dc voltage. [Circuit’s schematic diagram source:]

This entry was posted in Signal Processing, Test and Measurement and tagged . Bookmark the permalink.,
Possibly Related to "TMP01 AD654 Temperature-to-Frequency Converter" Circuits

  • TMP01 Fahrenheit Scale Temperature Sensor
    This schematic diagram is about TMP01 Fahrenheit Scale Temperature Sensor circuit. This circuit is used to convert VPTAT into an output that can be read directly in degrees Fahrenheit. The scale of this circuit is 10 mV/°F. This circuit consist … Continue reading →...
  • Buffering TMP01 Temperature Sensor
    This is a buffer circuit for TMP01 Temperature Sensor. The output of this sensor is a low impedance dc output voltage with a 5 mV/K temperature coefficient. This sensor can be used in multiple control and measurement applications. The buffered … Continue reading →...
  • TMP01 Celsius Scale Temperature Sensor
    The schematic diagram described here is a TMP01 Celsius Scale Temperature Sensor circuit. This circuit is used to convert the VPTAT output voltage that is calibrated in Kelvins into an output  in degrees Celsius on a voltmeter display. This circuit … Continue reading →...
  • Isolated Remote Temperature To Frequency Converter
    The following circuit shown in the schematic diagram converts temperature reading (from +30° to +30° F) to its corresponding frequency (30 to 3000 Hz). Other benefit is that a 4N28 isolate the output to protect the receiver from dangerous interference. … Continue reading →...
  • TMP01 Temperature Out-of-Range Warning
    This is a TMP01 temperature out-of-range warning circuit. This circuit is used to generate a temperature out-of-range warning signal. This circuit is usually used in sensitive equipment calibrated to work over a limited temperature range. This circuit can be done … Continue reading →...

Comments are closed.