DS1831/A/B

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PUSHBUTTON RESET SEQUENCING Figure 2

W resistor in the push-button input and

therefore does not require a pull-up resistor (an addition pull up can be used to accelerate responses). If an

external pull up is used in this example it must be connected to the 3.3V power supply.

OPERATION—PUSHBUTTON RESET

The DS1831 provides three pushbutton inputs for manual reset of the device. Pushbutton inputs for the

3.3V reset, 5V reset, and a master pushbutton reset (DS1831 and DS1831B only) input; provide multiple

options for system control. The 3.3V pushbutton reset and 5V pushbutton resets provide a simple manual

reset for the associated reset output; while the master pushbutton reset forces all resets and NMI outputs

active low.

The 5V reset pushbutton input and the 3.3V reset pushbutton input provide manual reset control input for

each associated reset output. When the output associated with a pushbutton input is not active, a

pushbutton is held low the reset will be forced active and will remain active for a reset cycle after the

pushbutton is released. See Figure 2 for an application example that allows a user to sequence the reset

outputs.

pin low for at least 20µs. When the pushbutton is held low all outputs are forced active and will remain

active for a reset or NMI time delay after the pushbutton is released. The Master Pushbutton input is

pulled high through an internal 100k

W pull up resistor and debounced via internal circuitry. See Figure 3

for an application example. Figures 4 and 5 for the timing diagram.

The 5V and 3.3V pushbutton reset inputs are pulled high through an internal 100k

W pull up resistor to the

voltage input, which is associated with that pushbutton. The master pushbutton is pulled to the greater of

GND

DS1831

5V Supply

3.3V Supply

1

2

3

4

5

16

15

14

13

12