MB95630H Series
MN702-00009-1v0-E
FUJITSU SEMICONDUCTOR LIMITED
285
CHAPTER 16 LOW-VOLTAGE DETECTION RESET CIRCUIT
16.4 Operation
16.4
Operation
The low-voltage detection reset circuit generates a reset signal if the power
supply voltage falls below the detection voltage.
■
Reset Threshold Voltage
In the case of changing the reset threshold voltage in the LVDR register, the new threshold
voltage does not start to take effect until the LVD reset threshold voltage transition
stabilization time (t
stb
) elapses. For details of t
stb
, refer to the device data sheet.
■
Operation of Low-voltage Detection Reset Circuit
The low-voltage detection reset circuit generates a reset signal if the power supply voltage falls
below the low-voltage detection voltage. Afterward, if the low-voltage detection reset circuit
detects the low-voltage detection reset release voltage, it outputs a reset signal lasting for the
oscillation stabilization wait time and then releases the reset.
For details of the electrical characteristics, refer to the device data sheet.
Figure 16.4-1 Operation of Low-voltage Detection Reset Circuit
■
Operation in Standby Mode
The low-voltage detection reset circuit keeps operating even in standby mode (stop mode, sleep
mode, subclock mode and watch mode).
Vcc
Re
s
et
s
ign
a
l
A: Del
a
y
B: O
s
cill
a
tion
s
t
ab
iliz
a
tion w
a
it time
Oper
a
ting volt
a
ge
lower limit
Detection volt
a
ge/
re
s
et rele
as
e volt
a
ge
A
A
A
B
B
B