ASM705 Datasheet, PDF (3/15 Pages) Alliance Semiconductor Corporation – Low Power UP Supervisor Circuits

April 2008
rev 1.6
Pin Description
ASM705/706
DIP/
SO
MicroSO
1
3
2
4
Pin Number
ASM707/708
DIP/
SO
MicroSO
1
3
2
4
ASM813L
DIP/
SO
MicroSO
1
3
2
4
Name
MR
V_CC
ASM705/706/707/708
ASM813L
Function
Manual reset input. The active LOW input
triggers a reset pulse. A 250 µA pull-up
current allows the pin to be driven by
TTL/CMOS logic or shorted to ground with a
switch.
+5V power supply input.
3
5
3
5
3
5
GND Ground reference for all signals.
Power-fail input voltage monitor. With PFI
4
6
4
6
4
6
PFI less than 1.25V, PFO goes LOW. Connect
PFI to Ground or V_CC when not in use.
Power-fail output. The output is active LOW
5
7
5
7
5
7
PFO and sinks current when PFI is less than
1.25V.
Watchdog input. WDI controls the internal
watchdog timer. A HIGH or LOW signal for
1.6sec at WDI allows the internal timer to
run-out, setting WDO LOW. The watchdog
6
8
-
-
6
8
WDI
function is disabled by floating WDI or by
connecting WDI to a high impedance three-
state buffer. The internal watchdog timer
clears when: RESET is asserted; WDI is
three-stated ; or WDI sees a rising or falling
edge.
-
-
6
8
-
-
NC Not Connected.
Active LOW reset output. Pulses LOW for
200ms when triggered, and stays LOW
whenever V_CC is below the reset threshold.
7
1
7
1
-
-
RESET remains LOW for 200ms after V_CC
RESET rises above the reset threshold or MR goes
from LOW to HIGH. 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 the
watchdog is cleared. In addition, when V_CC
8
2
-
-
8
2
WDO 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 goes
HIGH with no delay.
Active HIGH reset output. The inverse of
-
-
8
2
7
1
RESET RESET. The ASM813L only has a RESET
output.
Low Power µP Supervisor Circuits
Notice: The information in this document is subject to change without notice.
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