Independent Dsi Supply For Stm32F769Xx/Stm32F779Xx Devices; Battery Backup Domain; Voltage Regulator - ST STM32F7 Series Application Notes

Power supplies
1.1.4

Independent DSI supply for STM32F769xx/STM32F779xx devices

The DSI (Display Serial Interface) sub-system uses several power supply pins which are
independent from the other supply pins:
•
The V
DPHY. This supply must be connected to global V
•
The V
externally to V
•
The V
lanes pins. An external capacitor of 2.2 uF must be connected on V
•
The V
If the DSI functionality is not used at all, then:
•
The V
•
The V
is no more needed.
•
The V
1.1.5

Battery backup domain

Backup domain description
To retain the content of the RTC backup registers, backup SRAM, and supply the RTC when
V is turned off, V
DD
battery or by another source.
When the backup domain is supplied by V
V is not present), the following functions are available:
DD
•
PC14 and PC15 can be used as LSE pins only.
•
PC13 can be used as tamper pin (TAMP1).
•
PI8 can be used as tamper pin (TAMP2).
1.1.6

Voltage regulator

The voltage regulator is always enabled after reset. It works in three different modes
depending on the application modes.
• In Run mode, the regulator supplies full power to the 1.2 V domain (core, memories
and digital peripherals).
•
In Stop mode, the regulator supplies low power to the 1.2 V domain, preserving the
contents of the registers and SRAM.
•
In Standby mode, the regulator is powered down. The contents of the registers and
SRAM are lost except for those concerned with the standby circuitry and the backup
domain.
Note: Depending on the selected package, there are specific pins that should be connected either
to V or V
SS
section in the datasheet for more details.
10/54
is an independent DSI power supply dedicated for DSI Regulator and MIPI
DDDSI
pin is the output of DSI Regulator (1.2V) which must be connected
CAPDSI
.
DD12DSI
pin is used to supply the MIPI D-PHY, and to supply the clock and data
DD12DSI
pin is an isolated supply ground used for DSI sub-system.
DDDSI
pin must be connected to global V
DDDSI
pin must be connected externally to V
CAPDSI
pin must be grounded.
SSDSI
pin can be connected to an optional standby voltage supplied by a
BAT
to activate or deactivate the voltage regulator. Refer to the voltage regulator
DD
DocID027559 Rev 5
.
DD
.
DD
DD12DSI
(analog switch connected to V
BAT
AN4661
pin.
DD12DSI
but the external capacitor
because
BAT