MIC706P Datasheet, PDF (4/8 Pages) Micrel Semiconductor – μP Supervisory Circuits

MIC706P/R/S/T, MIC708R/S/T µP Supervisory Circuits
Pin Functions
Pin Name
Pin No.
MIC706 MIC706P
R/S/T
MR
1
1
VCC
2
2
GND
3
3
PFI
4
4
PFO
5
5
WDI
6
6
N/C
N/A
N/A
RESET
7
N/A
WDO
8
8
RESET
N/A
7
MIC708
1
2
3
4
5
N/A
6
7
N/A
8
Manual Reset Input forces reset outputs to assert when
pulled below 0.8V. An internal pull-up current of 250µA on
this input forces it high when left floating. This input can
also be driven from TTL or CMOS logic.
Primary supply input, +5V.
IC ground pin, 0V reference.
Power fail input. Internally connected to the power fail
comparator which is referenced to 1.25V. The power fail
output (PFO) remains high if PFI is above 1.25V. PFI
should be connected to GND or VOUT if the power fail
comparator is not used.
Power fail output. The power fail comparator is
independent of all other functions on this device.
Watchdog input. The WDI input monitors microprocessor
activity, an internal watchdog timer resets itself with each
transition on the watchdog input. If the WDI pin is held high
or low for longer than the watchdog timeout period, WDO is
forced to active low. The watchdog function cannot be
disabled.
No Connect
RESET is asserted if either VCC goes below the reset
threshold or by a low signal on the manual reset input (MR).
RESET remains asserted for one reset timeout period
(200ms) after VCC exceeds the reset threshold or after the
manual reset pin transitions from low to high. The
watchdog timer will not assert RESET unless WDO is
connected to MR.
Output for the watchdog timer. The watchdog timer resets
itself with each transition on the watchdog input. If the WDI
pin is held high or low for longer than the watchdog timeout
period, WDO is forced low. WDO will also be forced low if
VCC is below the reset threshold and will remain low until
VCC returns to a valid level.
RESET is the compliment of RESET and is asserted if
either VCC goes below the reset threshold or by a low
signal on the manual reset input (MR). RESET is suitable
for microprocessors systems that use an active high reset.
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