IN1232
M
ICRO
M
ONITOR
C
HIP
DESCRIPTION
The IN1232 MicroMonitor Chip monitors three vital conditions for a microprocessor: power supply,
software execution, and external override. First, a precision temperature–compensated reference and
comparator cir-
cuit monitors the status of V
CC.
When an out–of–tolerance condition occurs, an internal power fail
signal is generated which forces reset to the active state. When V
CC
returns to an in–tolerance
condition, the reset signals are kept in the active state for a minimum of 250 ms to allow the power
supply and processor to stabilize.
The second function the IN1232 performs is pushbutton reset control. The IN1232 debounces the
pushbutton input and guarantees an active reset pulse width of 250 ms minimum. The third function is
a watchdog timer. The IN1232 has an internal timer that forces the reset signals to the active state if
the strobe input is not driven low prior to time–out. The watchdog timer function can be set to operate
on time–out settings of approximately 150 ms, 600 ms, and 1.2 seconds.
FEATURES
Halts and restarts an out–of–control
microprocessor
Holds microprocessor in check during
power transients
Automatically restarts microprocessor
after power failure
Monitors pushbutton for external override
Accurate 5% or 10% microprocessor
power supply monitoring
Eliminates the need for discrete
components
Dip-8
PBRST
TD
TOL
GND
RST
RST
V
ST
CC
NC
SO-14
PIN DESCRIPTION
Pushbutton Reset Input
Time Delay Set
Selects 5% or 10% V
CC
Detect
Ground
Reset Output (Active High)
Reset Output (Active Low, open
drain)
Strobe Input
+5 Volt Power
No Connections
1
INTEGRAL [ INTEGRAL CORP. ]
