The TMP431 (two-channel) and TMP432 (three-channel) are digital temperature sensors that combine a local die temperature measurement channel and a remote junction temperature measurement channel in a single VSSOP-8 (TMP431) or VSSOP-10 (TMP432) package. They are Two-Wire- and SMBus interface-compatible and are specified over a temperature range of –40°C to 125°C. The TMP43x contain multiple registers for holding configuration information, temperature measurement results, temperature comparator maximum and minimum limits, and status information. User-programmed high and low temperature limits stored in the TMP43x can be used to trigger an overtemperature and undertemperature alarm (ALERT) on local and remote temperatures. Additional thermal limits can be programmed into the TMP43x and used to trigger another flag (THERM) that can be used to initiate a system response to rising temperatures.
For proper remote temperature sensing operation, the TMP431 requires only a transistor connected between DXP and DXN; the TMP432 requires transistors conncected between DXP1 and DXN1, and between DXP2 and DXN2.
The SCL and SDA interface pins require pullup resistors as part of the communication bus; ALERT and THERM are open-drain outputs that also need pullup resistors. ALERT and THERM can be shared with other devices if desired for a wired-OR implementation. TI recommends a 0.1-μF power-supply bypass capacitor for good local bypassing.