IMP706P/R/S/T/J, IMP708R/S/T/J
Pin Descriptions
Pin Number
IMP706P
IMP706R/S/T/J IMP708R/S/T/J
DIP/SO MicroSO DIP/SO MicroSO DIP/SO MicroSO Name
1
3
1
3
1
3
MR
Function
Manual reset input. The active LOW input triggers
a reset pulse. It is pulled HIGH by a 20kΩ pull-up
resistor. It is compatible with TTL/CMOS signals
when V
CC
= 5V. It can be shorted to ground
through a mechanical switch. Leave floating or
connect to V
CC
if the function is not used.
Monitored power supply input.
Ground
Power-fail input voltage monitor. With PFI less than
1.25V, PFO goes LOW. Connect PFI to ground
when not used.
Power-fail output. The output is active LOW and
sinks current when PFI is less than 1.25V. If not
used, leave the pin unconnected.
Watchdog input. WDI controls the internal watchdog
timer. A HIGH or LOW signal for 1.6 sec at WDI
allows the internal timer to run-out, setting WDO low.
A rising or falling edge must occur at WDI within
1.6 seconds or WDO goes LOW. The watchdog
function is disabled by floating WDI. The internal
watchdog timer clears when: RESET is asserted;
WDI is three-stated; or WDI sees a rising or falling edge.
Not connected.
Active-LOW reset output. Pulses LOW for 200ms
when triggered, and stays LOW whenever V
CC
is
below the reset threshold. RESET remains LOW for
200ms after V
CC
rises above the RESET threshold
or MR goes from HIGH to LOW. A watchdog timeout
will not trigger RESET unless WDO is connected to MR.
Watchdog output. WDO goes LOW when the 1.6
second internal watchdog timer times-out and does
not go HIGH until a transition occurs at WDI. In
addition, when V
CC
falls below the reset threshold,
WDO goes LOW. Unlike RESET, WDO does not have
a minimum pulse width and as soon as V
CC
exceeds
the reset threshold, WDO becomes HIGH with no delay.
Active-HIGH reset output. RESET is the inverse of
RESET.
2
3
4
4
5
6
2
3
4
4
5
6
2
3
4
4
5
6
V
CC
GND
PFI
5
7
5
7
5
7
PFO
6
8
6
8
—
—
WDI
—
—
—
—
6
8
NC
—
—
7
1
7
1
RESET
8
2
8
2
—
—
WDO
7
1
—
—
8
2
RESET
Feature Summary
IMP706P IMP706R IMP706S IMP706T IMP706J IMP708R IMP708S IMP708T IMP708J
Power-fail detector
I
I
I
I
I
I
I
I
I
Brownout detection
I
I
I
I
I
I
I
I
I
Debounced manual RESET input
I
I
I
I
I
I
I
I
I
Power-up/down RESET
I
I
I
I
I
I
I
I
I
Watchdog timer
I
I
I
I
I
Active-HIGH RESET
I
Active-LOW RESET
I
I
I
I
Active-LOW and HIGH RESETs
I
I
I
I
RESET threshold
2.63V
2.63V
2.93V
3.08V
4.00V
2.63V
2.93V
3.08V
4.00V
©
1999 IMP, Inc.
408-432-9100/www.impweb.com
5
IMP [ IMP, INC ]
