- T: Temperature
- Vout(T): Output
voltage as a function of temperature
- VPTC(T):
Voltage divider output voltage as a function of temperature. The voltage range
of VPTC(T) should not violate the input common mode range of
the amplifier
- RPTC(T):
Resistance of the PTC as a function of temperature
- Vbias:
Voltage source connected to PTC.
Equation 1.
Note: For this example the TMP61 10-kΩ Linear Thermistor is utilized.
Equation 1.
- Where RPTC(T) is defined as:
Equation 1.
- The constants
A4–A0 can be derived from the TMP61 design
tools for voltage dividers using a given Vbias and Rbias.
More information is found in the Thermistor Design
Tool (SBOC595).
- RPTC(T)
constants are specific to the Vbias selected.
- Rbias is defined as R1 in this example