The HD detector monitors the temperature of the die and provides a warning to the host processor through the interrupt system when temperature reaches a critical value. The threshold value must be set below the thermal shutdown threshold. Hysteresis is added to the HD detection to avoid the generation of multiple interrupts.
The integrated HD function provides the host PM software with an early warning overtemperature condition. This monitoring system is connected to the interrupt controller and can send an interrupt when the temperature is higher than the programmed threshold. The TPS65903x-Q1 devices allow the programming of four junction-temperature thresholds to increase the flexibility of the system: in nominal conditions, the threshold triggering of the interrupt can be set from 117°C to 130°C. The HD hysteresis is 10°C in typical conditions.
When an interrupt is triggered by the power-management software, immediate action must be taken to reduce the amount of power drawn from the TPS65903x-Q1 devices (for example, noncritical applications must be closed).