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Rev. 1.00
70 of 576
January 28, 2022
32-Bit Arm
®
Cortex
®
-M0+ MCU
HT32F54231/HT32F54241/HT32F54243/HT32F54253
5 Power Control Unit (PWRCU)
Features
▆
Two power domains: V
DD
and V
CORE
power domains
▆
Three power saving modes: Sleep, Deep-Sleep1 and Deep-Sleep2 modes
▆
Internal Voltage regulator supplies V
CORE
voltage source
▆
Additional ultra-low power voltage regulator supplies V
CORE
voltage source with low static
current and low operating current
▆
A power reset is generated when one of the following events occurs:
●
Power-on / Power-down reset (POR / PDR reset)
●
The control bits BODEN = 1, BODRIS = 0 and the supply power V
DD
≤ V
BOD
▆
The Brown-Out Detector can issue a system reset or an interrupt when V
DD
power source is lower
than the Brown-Out Detector voltage V
BOD
.
▆
The Low Voltage Detector can issue an interrupt or wakeup event when V
DD
is lower than a
programmable threshold voltage V
LVD
.
Functional Descriptions
V
DD
Power Domain
LDO Power Control
The main LDO(MLDO) and ultra-low power LDO (ULDO) will be automatically switched off
when the following condition occurs:
▆
The supply power V
DD
≤ V
PDR
The main LDO will be automatically switched on by hardware when the supply power V
DD
> V
POR
if any of the following conditions occurs:
▆
Resume operation from the power saving mode – RTC wakeup, LVD wakeup, EXTI wakeup and
WAKEUPn pin wakeup
▆
Detect a falling edge on the external reset pin (nRST)
▆
The control bit BODEN = 1 and the supply power V
DD
> V
BOD
To enter the Deep-Sleep1 or Deep-Sleep2 mode, the PWRCU will turn off the main LDO and
request the ULDO to operate in the low standby current mode to supply an alternative V
CORE
power.
Voltage Regulator
The main voltage regulator, LDO, ultra-low power LDO, ULDO, Low voltage Detector, LVD and
High Speed External Crystal oscillator, HSE, are operated under the V
DD
power domain. The main
LDO can be configured to operate in normal mode (LDOOFF = 0, LDOLCM = 0, I
OUT
= high
current mode) and the ultra-low power LDO can be configured to operate in low current mode
(LDOOFF = 0, LDOLCM = 1, I
OUT
= low current mode) to supply the V
CORE
power. The ULDO
output has ultra-low static current characteristics and can be configured to operate in the Deep-
Sleep2 mode for data retention purposes in the V
CORE
power domain. It is controlled using the
ULDOON bit in the PWRCR register.
Power-On Reset (POR) / Power-Down Reset (PDR)
The devices have an integrated POR/PDR circuitry that allows proper operation starting from V
POR
or down to V
PDR
. For more details concerning the power-on/power-down reset threshold voltage,
refer to the electrical characteristics of the corresponding datasheet.