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TMP64

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SNIS212 – DECEMBER 2019

Product Folder Links: TMP64

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8 Application and Implementation

NOTE

Information in the following applications sections is not part of the TI component

specification, and TI does not warrant its accuracy or completeness. TI’s customers are

responsible for determining suitability of components for their purposes. Customers should

validate and test their design implementation to confirm system functionality.

8.1 Application Information

The TMP64 is a positive temperature coefficient (PTC) linear silicon thermistor. The device behaves like a

temperature-dependent resistor, and may be configured in a variety of ways to monitor temperature based on the

system-level requirements. The TMP64 has a nominal resistance at 25 °C (R25) of 47 kΩ, a maximum operating

applications to monitor temperature close to a heat source with the very small DEC package option compatible

with the typical 0402 (inch) footprint. Some of the factors that influence the total measurement error include the

ADC resolution (if applicable), the tolerance of the bias current or voltage, the tolerance of the bias resistance in

the case of a voltage divider configuration, and the location of the sensor with respect to the heat source.

8.2 Typical Application

8.2.1 Thermistor Biasing Circuits

Figure 6. Biasing Circuit Implementations With Linear Thermistor (Left) vs. Non-Linear Thermistor

(Right)

8.2.1.1 Design Requirements

Existing thermistors, in general, have a non-linear temperature vs. resistance curve. To linearize the thermistor

response, the engineer can use a voltage linearization circuit with a voltage divider configuration, or a resistance

the thermistor, the engineer can use a voltage divider circuit with the thermistor placed at either the high side

(close to supply) or low side (close to ground), depending on the desired voltage response (negative or positive).

Alternatively, the thermistor can be biased directly using a precision current source (yielding the highest accuracy