Most RTD applications use a current source to excite the RTD element and create a voltage difference. The TMP61 is a linear silicon-based thermistor that has consistent sensitivity across temperature. Using the TMP61 in a current biasing circuit such as Figure 2-6 can offer a method of temperature monitoring to replace the expense and complexity of RTDs. The TMP61 has a positive temperature slope and a temperature measurement range of –40°C to 125°C. The TMP61 can also be used in a voltage biasing circuit, seen in Figure 2-7. The output voltage that corresponds to the measured temperature, V_TEMP , is measured across R_BIAS.

Figure 2-6 TMP61 Current Biasing Circuit

Figure 2-7 TMP61 Voltage Biasing Circuit