ZHCSIF4C June 2018 – April 2021 TMP117
The TMP117 operates only as a slave device and communicates with the host through the I2C-compatible serial interface. SCL is the input pin, SDA is a bidirectional pin, and ALERT is the output. The TMP117 requires a pullup resistor on the SDA, and ALERT pins. The recommended value for the pullup resistors is 5 kΩ. In some applications, the pullup resistor can be lower or higher than 5 kΩ. A 0.1-µF bypass capacitor is recommended to be connected between V+ and GND. An SCL pullup resistor is required if the system microprocessor SCL pin is open-drain. Use a ceramic capacitor type with a temperature rating that matches the operating range of the application, and place the capacitor as close as possible to the V+ pin of the TMP117. The ADD0 pin can be connected directly to GND, V+, SDA and SCL for address selection of four possible unique slave ID addresses. Table 7-1 explains the addressing scheme. The ALERT output pin can be connected to a microcontroller interrupt that triggers an event that occurred when the temperature limit exceeds the programmable value in registers 02h and 03h. The ALERT pin can be left floating or connected to ground when not in use.