8.2.2.2 Detailed Design Procedure

SETA sets the +90°C threshold using 78.7 kΩ. SETB sets the +60°C trip point and 10°C hysteresis using 249 kΩ. These values were determined using Table 1 and Table 2. These resistors should have maximum of 1% tolerance at room temperature and 100 ppm/°C or less over the desired temperature range. A summary of the resistor settings used in this example is shown in Table 3. See Table 1 and Table 2 for additional trip points and hysteresis configurations.

The switching output of the TMP392 can be visualized with the output diagram shown in Figure 12. It is key to notice that hysteresis is subtracted from both Channel A and Channel B threshold values. OUTA remains high until the sensor reaches +90°C where the output goes low, and returns high after the temperature drops back down to +80°C. OUTB remains high until the sensor reaches +60°C where the output goes low, and returns high after the temperature drops back down to +50°C.