IMP706P/R/S/T/J, IMP708R/S/T/J
Pin Descriptions
Pin Number
IMP706R/S/T/J IMP708R/S/T/J
DIP/SO MicroSO DIP/SO MicroSO DIP/SO MicroSO Name
IMP706P
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 VCC = 5V. It can be shorted to ground
through a mechanical switch. Leave floating or
connect to VCC if the function is not used.
1
3
1
3
1
3
MR
2
3
4
5
2
3
4
5
2
3
4
5
VCC
GND
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.
4
5
6
7
4
5
6
7
4
5
6
7
PFI
PFO
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.
6
8
6
8
—
—
WDI
—
—
—
—
—
—
6
7
8
1
NC
Not connected.
Active-LOW reset output. Pulses LOW for 200ms
when triggered, and stays LOW whenever VCC is
below the reset threshold. RESET remains LOW for
200ms after VCC 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.
7
1
RESET
Watchdog output.
goes LOW when the 1.6
WDO
second internal watchdog timer times-out and does
not go HIGH until a transition occurs at WDI. In
addition, when VCC falls below the reset threshold,
WDO goes LOW. Unlike RESET, WDO does not have
a minimum pulse width and as soon as VCC exceeds
the reset threshold, WDO becomes HIGH with no delay.
8
7
2
1
8
2
—
—
WDO
—
—
8
2
RESET
Active-HIGH reset output. RESET is the inverse of
RESET.
Feature Summary
IMP706P IMP706R IMP706S IMP706T IMP706J IMP708R IMP708S IMP708T IMP708J
Power-fail detector
Brownout detection
Debounced manual RESET input
Power-up/down RESET
Watchdog timer
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Active-HIGH RESET
Active-LOW RESET
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Active-LOW and HIGH RESETs
RESET threshold
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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 ]
