6.3.7 Thermal Monitoring
The TPS65903x-Q1 devices include several thermal monitoring functions:
- Thermal protection module internal to the TPS65903x-Q1 devices, placed close to the SMPS and LDO modules
- Platform temperature monitoring with an external NTC resistor
- Platform temperature monitoring with an external diode
The TPS65903x-Q1 devices integrate two thermal detection modules to monitor the temperature of the die. These modules are placed on opposite sides of the chip and close to the LDO and SMPS modules. Overtemperature at either module generates a warning to the system; if the temperature continues to rise, the TPS65903x-Q1 devices shut down before damage to the die can occur.
Thus, there are two protection levels:
- A hot-die (HD) function sends an interrupt to software. Software is expected to close any noncritical running tasks to reduce power.
- A thermal shutdown (TS) function immediately starts the TPS65903x-Q1 device switch-off.
By default, thermal protection is always enabled except in the BACKUP or OFF state. Disabling thermal protection in SLEEP mode for minimum power consumption is possible.
To use thermal monitoring in the system:
- Set the value for the HD temperature threshold with the OSC_THERM_CTRL.THERM_HD_SEL[1:0] register.
- TS can be disabled in SLEEP mode by setting the THERM_OFF_IN_SLEEP bit to 1 in the OSC_THERM_CTRL register.
- During operation, if the die temperature increases above HD_THR_SEL, an interrupt (INT1.HOTDIE) is sent to the host processor. Immediate action to reduce TPS65903x-Q1 power dissipation must be taken by shutting down some function.
- If the die temperature of the TPS65903x-Q1 devices rise further (above 148°C) an immediate shutdown occurs. A TS event indication is written to the status register, INT1_STATUS_HOTDIE. The system cannot restart until the temperature falls below HD_THR_SEL.