The TPS389006 is in ACTIVE state when ACT is High.

VMON monitors high frequency channel levels (copmarator sense path) and low frequency channel levels (ADC sense path) against Under-Voltage High Frequency (UVHF), Over-Voltage High Frequency (OVHF), Under-Voltage Low Frequency (UVLF), and Over-Voltage Low Frequency (OVLF) thresholds.

Some channels can be connected to rails which are controlled by user software. Such channels can be in the OFF state (below the OFF threshold) when the TPS389006 is in an ACTIVE state, and have the UVLF/UVHF interrupts normally disabled. Once these rails are turned ON, the TPS389006 host enables the channels UVLF/UVHF interrupts to allow full monitoring. Similarly, before these rails are turned OFF, the TPS389006 host disables the channels UVLF/UVHF interrupts to avoid false UV violations during the ramp down. As these channels are not part of the sequencing initiated by ACT or SLEEP, their UVLF/UVHF/OVHF interrupts cannot be automatically enabled/disabled using the auto-mask registers. While in the OFF state, only the OVLF thresholds are monitored to ensure the reliability limits are not violated.

Other enabled channels can be in OFF state as a result of the SLEEP 1→0 transition sequence. Those channels are identified by the AMSK_ENS auto-mask register, used to avoid UVLF interrupts (as well as UVHF and OVHF interrupts) during the transition. For those channels in the OFF state and identified by the AMSK_ENS register, only the OVLF thresholds are monitored to ensure the reliability limits are not violated.