SNVSC07A June 2021 – September 2022 LP876242-Q1
PRODUCTION DATA
The LP876242-Q1 device includes several thermal monitoring functions for internal thermal protection of the PMIC.
The LP876242-Q1 device integrates thermal detection modules to monitor the temperature of the die. These modules are placed on opposite sides of the device and close to the BUCK modules. An over-temperature condition at either module first generates a warning to the system, and if the temperature continues to rise, then a switch-off of the PMIC device can occur before damage to the die.
Three thermal protection levels are available. One of these protections is a thermal warning function described in Section 7.3.6.1, that sends an interrupt to software. Software is expected to close any noncritical running tasks to reduce power. The second and third protections are the thermal shutdown (TS) function described in Section 7.3.6.2, that begins device shutdown orderly or immediately.
Thermal monitoring is automatically enabled when one of the BUCK outputs is enabled within the mission states. The thermal monitoring is disabled in the LP_STANDBY state, when only the internal regulator is enabled, to minimize the device power consumption. Indication of a thermal warning event is written to the TWARN_INT register.
The current consumption of the thermal monitoring can be decreased in the mission states when the low power dissipation is important. If LPM_EN bit is set and the temperature is below thermal warning level in all thermal detection modules, only one thermal detection module is monitored. If the temperature rises in this module, monitoring in all thermal detection modules is started.
If the die temperature of the LP876242-Q1 device continues to rise while the device is in mission state, an TSD_ORD_INT or TSD_IMM_INT interrupt is generated, causing a SEVERE or MODERATE error trigger (respectively) in the state machine. While the sequencing and error handling is NVM memory dependent, TI recommends a sequenced shutdown for MODERATE errors, and an immediate shutdown, using resistive discharging, for SEVERE errors to prevent damage to the device. The system cannot restart until the temperature falls below the thermal warning threshold.