TI smart power stages sense their internal die temperature and output temperature information as a voltage signal through their TAO pins. The temperature sense output of the powerstage device includes an OR'ing function such that the voltage signal present at the TSEN pin of the TPS53676 represents that of the hottest powerstage in the channel. The TPS53676 digitizes its TSEN pins to provide temperature telemetry.

• Overtemperature fault (OTF) is a programmable threshold which sets the maximum allowed temperature of the powerstage devices attached to a channel. Detection is based on output temperature telemetry. When the sensed temperature for a channel exceeds this limit, the overtemperature fault condition is detected. Program this threshold using the OT_FAULT_LIMIT command. TPS53676 supports values of 90 to 160 °C.
• Overtemperature warning (OTW) is a programmable threshold which sets a warning based on the temperature sense telemetry for a channel. Detection is based on temperature sense telemetry. When the sensed temperature for a channel exceeds this limit, the overtemperature warning is detected. Program this threshold using the OT_WARN_LIMIT. TPS53676 supports values of 90 to 160 °C.

In response to the overtemperature warning condition, TPS53676 sets the appropriate status bits in STATUS_WORD and STATUS_TEMPERATURE and asserts the SMB_ALERT# line if these bits are not masked.

In response to the overtemperature fault condition, TPS53676 responds according to the programmed OT_FAULT_RESPONSE. When not set to the ignore response, this causes the PWM pins of the rail which experienced a fault to tristate immediately. TPS53676 then sets the appropriate status bits in STATUS_WORD and STATUS_TEMPERATURE and asserts the SMB_ALERT# line if these bits are not masked.