R5101G RICOH Co.,Ltd., R5101G Datasheet - Page 11

• Manufacturer Part Number: R5101G
• Description: Microprocessor Power Management With Watchdog Timer
• Manufacturer: RICOH Co.,Ltd.

OPERATION
M When V
N An External Capacitor starts to be charged through the C
O When the voltage level of V
P The operation mode for the external capacitor changes from charging mode to discharging mode through C
Q While the C
R While the C
S C
T The Output Voltage level of RESET pin becomes from “H” to “L”, or a Reset signal is generated when an
U The watchdog timer will be halted when a Voltage level of CE pin becomes to “L”. In this case, only the
∗ t
∗ Watchdog Timeout period, t
∗ Reset timeout period of the watchdog timer, t
becomes “L” level.
Regulator, V
until Voltage of the C
“H” level.
the voltage level of V
t
13000 × C
C
TW
the pulse), the operation mode of C
external capacitor connected to C
to CLK pin, the voltage level of Reset pin becomes from “H” to “L”.
t
(ms) ≈ 10000 × C
Vref2L to Vref2H. t
output voltage of the Voltage Regulator drops to a level at equal or less than -V
watchdog timer is stopped and monitoring the output voltage is continued. After that, if the voltage level of
CE pin becomes to “H”, C
PR
PR
WD
TW
TW
: Time interval between the timing of starting edge of forcing voltage to V
pin when the voltage level of C
can be set by connecting an external capacitor to C
can be set by connecting an external capacitor to C
pin and the watchdog timer begins to operate.
pin is changed to charging mode from discharging mode when the Reset signal is generated.
DD
D
is turned on and Input Voltage reaches Vstart (nearly equal 0.8V), the output of RESET pin
(µF); C
TW
TW
OUT
pin is on the discharging mode, if a clock pulse is entered (synchronous with a rising edge of
pin is on the discharging mode, if V
, crosses the Released Voltage, +V
W
D
WR
(µF); C
means a value of an external capacitor connected to C
RESET
D
can be calculated by the next equation as shown below; t
pin, V
W
TW
.
CD
WD
means a value of an external capacitor connected to C
CD
pin starts to be on charging mode.
reaches to the Vref2H, the external capacitor starts to be charged through the
,: Discharging Time of C
, reaches to the Vref2H, about 1.0V, and after that the V
TW
TW
pin, V
pin is charged until its voltage level reaches to Vref2H.
TW
pin changes from discharging mode to charging mode. And the
CTW
WR
, reaches to the Vref2H.
,: Time interval between Charging time of the C
CTW
DET
, from Lower to Higher. The V
D
TW
level drops to Vref2L, about 0.2V without clock pulse
pin, t
pin level from Vref2H to Vref2L
W
pin, t
D
PR
pin when an Output Voltage of the Voltage
can be calculated as shown below; t
WD
can be calculated as shown below; t
D
DD
pin.
pin and the timing of reverse
WR
DET
(ms) ≈ t
.
W
pin.
RESET
RESET
WD
/10
is kept “L” level
becomes to
TW
R5101G
PR
pin from
(ms) ≈
WD
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