CAT823, CAT824, CAT825

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5

FUNCTIONAL DESCRIPTION

Processor RESET

provide a reset output to maintain correct system operation.

On power−up, RESET (and RESET if available) are kept

(and RESET) are pulled active. RESET (and RESET if

available) is specifically designed to provide the reset input

signals for processors. This provides reliable and consistent

operation as power is turned on, off or during brownout

conditions by maintaining the processor operation in known

conditions.

Manual RESET

The CAT823 and CAT825 each have a Manual Reset

(MR) input to allow for alternative control of the reset

outputs. The MR input is designed for direct connection to

a pushbutton (see Figure 4). The MR input is internally

pulled up by 52 k

W resistor and must be pulled low to cause

the reset outputs to go active. Internally, this input is

debounced and timed such that RESET (and RESET)

signals of at least 140 ms minimum will be generated. The

is released from the low level. (see Figure 5)

RESET

CAT825

GND

Supply

Voltage

Figure 4. Pushbutton RESET

MR

RESET

Figure 5. Timing Diagram – Pushbutton RESET

RESET

RESET

MR