ADM705–ADM708

REV. B

–3–

PIN FUNCTION DESCRIPTION

Pin No.

ADM705

ADM707

ADM706

ADM708

Mnemonic

DIP, SOIC

DIP, SPOC

MicroSOIC

Function

MR

1

1

3

Manual Reset Input. When taken below 0.8 V, a RESET is gener-

ated.

MR can be driven from TTL, CMOS logic or from a manual

reset switch as it is internally debounced. An internal 250

µA pull-up

current holds the input high when floating.

2

2

4

5 V Power Supply Input.

GND

3

3

5

0 V. Ground reference for all signals.

PFI

4

4

6

Power-Fail Input. PFI is the noninverting input to the Power-Fail

Comparator. When PFI is less than 1.25 V,

PFO goes low. If unused,

PFO

5

5

7

Power-Fail Output.

PFO is the output from the Power-Fail Compara-

tor. It goes low when PFI is less than 1.25 V.

WDI

6

N/A

N/A

Watchdog Input. WDI is a three-level input. If WDI remains either

high or low for longer than the watchdog timeout period, the watch-

dog output

WDO goes low. The timer resets with each transition at

the WDI input.

Either a high-to-low or a low-to-high transition will clear the counter.

The internal timer is also cleared whenever reset is asserted. The

watchdog timer is disabled when WDI is left floating or connected to

a three-state buffer.

NC

N/A

6

8

No Connect.

RESET

7

7

1

Logic Output.

RESET goes low for 200 ms when triggered. It can be

signal on the manual reset (

MR) input. RESET will remain low

reset threshold or

MR goes from low to high. A watchdog timeout

will not trigger

RESET unless WDO is connected to MR.

WDO

8

N/A

N/A

Logic Output. The Watchdog Output,

WDO, goes low if the internal

watchdog timer times out as a result of inactivity on the WDI input. It

remains low until the watchdog timer is cleared.

WDO also goes low

WDO remains low. As soon as V

WDO goes high immediately.

RESET

N/A

8

2

Logic Output. RESET is an active high output suitable for systems

that use active high RESET logic. It is the inverse of

RESET.

PIN CONFIGURATION

DIP, SOIC

DIP, SOIC

MicroSOIC

1

2

3

4

8

7

6

5

TOP VIEW

(Not to Scale)

NC = NO CONNECT

ADM707/

ADM708

RESET

GND

PFI

PFO

NC

RESET

MR

8

7

6

5

1

2

3

4

TOP VIEW

(Not to Scale)

ADM705/

ADM706

MR

PFO

WDI

RESET

WDO

GND

PFI

8

7

6

5

1

2

3

4

TOP VIEW

(Not to Scale)

NC = NO CONNECT

ADM707/

ADM708

MR

PFO

NC

RESET

RESET

GND

PFI