Datasheet
TC1232
DS21370D-page 6 Preliminary 2002-2012 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
= 150 ms
TD = Open t
TD
= 600 ms
TD = V
CC
t
TD
= 1.2 sec
3 6 TOL I ST Tolerance Input.
TOL = GND, Max Voltage Trip Point (V
CCTP
) = 4.75V (5% tolerance)
TOL = V
CC
, Max Voltage Trip Point (V
CCTP
) = 4.5V (10% tolerance)
4 8 GND — P The ground reference for the device.
59RSTOPush
Pull
Reset Output (Active-High)
Goes active (High) if one of these conditions occurs:
1. If V
CC
falls below the selected reset voltage threshold.
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
611RST
O Open
Drain
Reset Output (Active-Low)
Goes active (Low) if one of these conditions occurs:
1. If V
CC
falls below the selected reset voltage threshold.
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)
815V
CC
— P The positive supply (+5V) for the device.
— 1,3,5,
7,10,1
2,16
NC — — No internal connection.