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Rev. 1.40
106
March 29, 2019
Rev. 1.40
107
March 29, 2019
HT45F23A/HT45F24A
TinyPower
TM
Flash MCU with OPA & Comparators
HT45F23A/HT45F24A
TinyPower
TM
Flash MCU with OPA & Comparators
LDO Function
The devices contain a low power voltage regulator implemented in CMOS technology. Using
CMOS technology ensures low voltage drop and low quiescent current. There are two fixed output
voltages of 2.4V and 3.3V, which can be controlled by a specific register. The internal LDO output
combined with various options by register can provide a fixed voltage for the LCD bias voltage, the
OPA reference voltage, the ADC reference voltage and as a fixed power supply for external device.
LDOC Register
Bit
7
6
5
4
3
2
1
0
Name
—
—
—
VLOE
REN1
VRES
VSEL
LDOEN
R/W
—
—
—
R/W
R/W
R/W
R/W
R/W
POR
—
—
—
0
0
0
0
0
Bit 7~5
unimplemented, read as "0"
Bit 4
VLOE
: LDO output voltage control bit
0: disable
1: enable
If the VLOE and LDOEN are set to “1”, the LDO will output 2.4V or 3.3V to pin and
disable I/O function.
Bit 3
REN1
: Bias voltage divided resistor control bit
0: disable
1: enable
If the REN1is set to “1”, that will turn on the resistor DC path, which will generate
bias voltage for OPAs or LCD SCOM.
Bit 2
VRES
: Divided resistor voltage supply selection bit
0: VDD
1: VLDO
Note that the VRES bit will be cleared to 0 by hardware if the LDO is disabled by
setting the LDOEN bit low.
Bit 1
VSEL
: LDO output voltage selection bit
0: 2.4V
1: 3.3V
Bit 0
LDOEN
: LDO control bit
0: disable
1: enable