S1410 datasheet(7/29 Pages) SII

7 / 29 page

LOW CURRENT CONSUMPTION WATCHDOG TIMER WITH RESET FUNCTION

Rev.1.0_01

S-1410/1411 Series

Seiko Instruments Inc.

4. CWDT pin

This is a pin to connect an external capacitor in order to generate the watchdog time-out period (tWDU) and the

watchdog double pulse detection time (tWDL). The capacitor is charged and discharged by an internal constant

current circuit.

tWDU is calculated by using the following equation.

tWDU = 50,000,000

× CWDT [F] + 0.0011

Moreover, tWDL is calculated by using the following equation.

tWDL =

tWDU

5. WEN pin

This is a pin to switch Enable / Disable of the watchdog timer.

When the WEN pin logic is active "H", the watchdog timer becomes Enable if the input is "H", and the

charge-discharge operation is performed at the CWDT pin. In the active "H" product, the WEN pin has a built-in

pull-down resistor.

6. WDO

_________

This pin combines the reset output and the watchdog output.

Be sure to connect a pull-up resistor to the WDO

________

pin in the product without an output pull-up resistor.

7. WDI pin

This is an input pin to receive a signal from the monitored object. By being input an edge at an appropriate timing, the

WDI pin confirms the normal operation of the monitored object.

The WDI pin has a built-in pull-down resistor.

S1410 Datasheet(PDF) 7 Page - Seiko Instruments Inc