Rev. 1.00
88
August 29, 2018
Rev. 1.00
89
August 29, 2018
HT45F6530
AC Voltage Regulator Flash MCU
HT45F6530
AC Voltage Regulator Flash MCU
Bit 5
LVDO
: LVD Output Flag
0: No Low Voltage Detect
1: Low Voltage Detect
Bit 4
LVDEN
: Low Voltage Detector Control
0: Disable
1: Enable
Bit 3
VBGEN
: Bandgap Buffer Control
0: Disable
1: Enable
Note that the Bandgap circuit is enabled when the LVD or LVR function is enabled or
when the VBGEN bit is set to 1.
Bit 2~0
VLVD2~VLVD0
: Select LVD Voltage
000: 2.0V
001: 2.2V
010: 2.4V
011: 2.7V
100: 3.0V
101: 3.3V
110: 3.6V
111: 4.0V
LVD Operation
The Low Voltage Detector function operates by comparing the power supply voltage, V
DD
, with a
pre-specified voltage level stored in the LVDC register. This has a range of between 2.0V and 4.0V.
When the power supply voltage, V
DD
, falls below this pre-determined value, the LVDO bit will be
set high indicating a low power supply voltage condition. When the device is in the SLEEP mode,
the low voltage detector will be disabled even if the LVDEN bit is high. After enabling the Low
Voltage Detector, a time delay t
LVDS
should be allowed for the circuitry to stabilise before reading the
LVDO bit. Note also that as the V
DD
voltage may rise and fall rather slowly, at the voltage nears that
of V
LVD
, there may be multiple bit LVDO transitions.
V
DD
LVDEN
LVDO
V
LVD
t
LVDS
LVD Operation
The Low Voltage Detector also has its own interrupt, providing an alternative means of low voltage
detection, in addition to polling the LVDO bit. The interrupt will only be generated after a delay of
t
LVD
after the LVDO bit has been set high by a low voltage condition. In this case, the LVF interrupt
request flag will be set, causing an interrupt to be generated if V
DD
falls below the preset LVD
voltage. This will cause the device to wake-up from the IDLE Mode, however if the Low Voltage
Detector wake up function is not required then the LVF flag should be first set high before the device
enter the IDLE Mode.