
Rev. 1.00
61 of 486
July 31, 2018
32-Bit Arm
®
Cortex
®
-M0+ MCU
HT32F50231/HT32F50241
5 Power Control Unit (PWRCU)
Features
▄
Three power domains: V
DD,
V
DDIO
and V
DD15
1.5 V power domains.
▄
Three power saving modes: Sleep, Deep-Sleep1 and Deep-Sleep2 modes.
▄
Internal Voltage regulator supplies 1.5 V voltage source.
▄
Additional Depletion MOS supplies 1.5 V voltage source with low leakage 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
.
▄
BOD 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
.
▄
LVD 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 LDO will be automatically switched off when the following condition occurs:
▄
The Deep-Sleep2 mode is entered.
The 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
WAKEUP pins.
▄
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 mode, the PWRCU will request the LDO to operate in a low current
mode, LCM. To enter the Deep-Sleep2 mode, the PWRCU will turn off the LDO and turn on the
DMOS to supply an alternative 1.5 V power.
Voltage Regulator
The voltage regulator, LDO, Depletion MOS, DMOS, Low voltage Detector, LVD, Low Speed
Internal RC oscillator, LSI, Low Speed External Crystal oscillator, LSE, and the High Speed External
Crystal oscillator, HSE, are operated under the V
DD
power domain. The LDO can be configured
to operate in either normal mode (LDOOFF = 0, LDOLCM = 0, I
OUT
= High current mode) or low
current mode (LDOOFF = 0, LDOLCM = 1, I
OUT
= Low current mode) to supply the 1.5 V power. An
alternative 1.5 V power source is the output of the DMOS which has low static and driving current
characteristics. It is controlled using the DMOSON bit in the PWRCR register. The DMOS output has
weak output current and regulation capability and only operates in the Deep-Sleep2 mode for data
retention purposes in the V
DD15
power domain.
Power On Reset (POR) / Power Down Reset (PDR)
The device has an integrated POR / PDR circuitry that allows proper operation starting from
V
POR
. For more details concerning the power on / power down reset threshold voltage, refer to the
electrical characteristics of the corresponding datasheet.