4

Manual Reset Input forces reset outputs to assert when

pulled below 0.8V. An internal pull-up current of 250

µAon

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.

Pin No.

Pin Name

MIC706

MIC706P

MIC708

R/S/T

MR

11

1

VCC

22

2

GND

33

3

PFI

44

4

PFO

55

5

WDI

6

6

N/A

N/C

N/A

N/A

6

RESET

7

N/A

7

WDO

8

8

N/A

RESET

N/A

7

8

Pin Functions

MIC706P/R/S/T, MIC708R/S/T

µP Supervisory Circuits