S-1411 Datasheet, PDF (7/36 Pages) –

LOW CURRENT CONSUMPTION WATCHDOG TIMER WITH RESET FUNCTION
Rev.2.0_00
S-1410/1411 Series
 Pin Functions
Refer to " Operation" for details.
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1. W / T pin (S-1410 Series only)
This is a pin to switch the watchdog mode.
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The S-141_{_}0_{__} Series changes to the time-out mode when the W / T pin is "H", and changes to the window mode
when the W / T pin is "L". Switching the mode is prohibited du_{__}r_{_}ing the operation.
The constant current source (0.3 μA typ.) is connected to the W / T pin, and it is pulled down internally.
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1. 1 Time-out mode (W / T pin = "H")
The S-1410 Series detects an abnormality whe_{__}n_{___}n_{__}o_{_}t inputting an edge to the WDI pin during the watchdog time-out
period (t_WDU). And then "L" is output from the WDO pin.
W / T _"H"
(S-1410 only)
WDI
(Rising edge)
WDO
tWDU
tRST
Figure 5 Abnormality Detection in Time-out Mode
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1. 2 Window mode (W / T pin = "L")
When not inputting an edge to the WDI pin during t_WDU, or when an edge is input to the WDI pin again within a
specific period of time (the discharge_{____}ti_{_}m_{___}e due to an edge detection + 1 charge-discharge time (t_WDL)) after
inputting an edge to the WDI pin, the WDO pin output changes from "H" to "L".
W / T "L"
(S-1410 only)
WDI
(Rising edge)
WDO
tWDL
tRST
tWDU
tRST
Figure 6 Abnormality Detection in Window Mode
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2. RST pin (S-1411 Series only)
This is a reset output pin. It outputs "L" when_{__}d_{__}e_{__}t_{_}ecting a low voltage.
Be sure to connect a pull-up resistor to the RST pin in the product without an output pull-up resistor.
3. CPOR pin
This is a pin to connect an external capacitor in order to generate the reset time-out period (t_RST).
The capacitor is charged and discharged by an internal constant current circuit, and the charge-discharge duration is
t_RST.
t_RST is calculated by using the following equation.
t_RST = 6,500,000 × C_POR [F] + 0.0002
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