TC1232

DS20001370E-page 6

 2002-2014 Microchip Technology Inc.

3.0

PIN DESCRIPTIONS

The descriptions of the pins are listed in Table 3-1.

TABLE 3-1:

PIN FUNCTION TABLES

Pin No.

Symbol

Pin

Type

Buffer/

Driver

Type

Function

8-pin

PDIP,

SOIC

16-pin

SOIC

1

2

PB RST

I

ST

Push Button Reset Input.

Input for a Manual Reset Switch. This input debounces (ignores) pulses

less than 1 ms in duration and is ensured to recognize inputs of 20 ms or

greater.

L = Manual Reset Switch is Active, Force RST/RST pins Active

H = Manual Reset Switch is Inactive. State of RST/RST pins determined by

other system conditions.

2

4

TD

I

ST

Time Delay Input.

The voltage level on this input determines the Watchdog Timer Time-out

period.

TD = 0V

 t

TD = Open

 t

 t

3

6

TOL

I

ST

Tolerance Input.

4

8

GND

—

P

The ground reference for the device.

59

RST

O

Push

Pull

Reset Output (Active-High)

Goes active (High) if one of these conditions occurs:

1.

2.

If PB RST pin is forced low.

3.

If ST pin is not strobed within the minimum selected time-out period.

(see TD pin)

4.

During power-up.

611

RST

O

Open

Drain

Reset Output (Active-Low)

Goes active (Low) if one of these conditions occurs:

1.

2.

If PB RST pin is forced low.

3.

If ST pin is not strobed within the minimum selected time-out period.

(see TD pin)

4.

During power-up.

713

ST

I

ST

Strobe Input

Input for Watchdog Timer. WDT period determined by state of TD pin

Falling Edge

 Resets Watchdog Timer counter (no time-out)

815

—

P

The positive supply (+5V) for the device.

—

1,3,5,

7,10,1

2,16

NC

—

—

No internal connection.