SLVSCO4D July 2015 – February 2019 TPS65917-Q1
The LDOVRTC regulator supplies always-on functions, such as wake-up functions. This power resource is active as soon as a valid energy source is present.
This resource has two modes which are Normal mode and backup mode. The LDOVRTC regulator functions in normal mode when supplied from the main system power rail and is able to supply all digital components of the TPS65917-Q1 device. The LDOVRTC regulator functions backup mode when supplied from system power rail that is above the power-on reset threshold but below the system low threshold and is only able to supply always-on components.
The LDOVRTC regulator supplies the digital components of the TPS65917-Q1 device. In the BACKUP state, the digital activity is reduced to maintaining the wake up functions only. In the OFF state, the turn-on events and detection mechanism are added to the previous current load in the BACKUP state. In the BACKUP and OFF states, the external load on the LDOVRTC pin should not exceed 0.5 mA. In the ACTIVE state, the LDOVRTC switches automatically into active mode. The reset is released and the clocks are available. In SLEEP state, the LDOVRTC is kept active. The reset is released and only the 32-kHz clock is available. To reduce power consumption, the user is still able to select low-power mode through the software.
If VCC is discharged rapidly and then resupplied, a POR may not be reliably generated. In this case a pulldown resistor can be added on the LDOVRTC output. See Section 5.15 for details.