ASM690A/692A

ASM802L/802M

April 2008

ASM805L

rev 1.7

µP Power Supply Supervisor With Battery Backup Switch

2 of 15

Notice: The information in this document is subject to change without notice.

Pin Configuration

Pin Description

Pin Number

ASM690A/

ASM692A

ASM802L/

ASM802M

ASM805L

Name

Function

1

1

power to the CMOS RAM.

2

2

+5V power supply input.

3

3

GND

Ground

4

4

PFI

Power failure monitor input. PFI is connected to the internal power fail

comparator which is referenced to 1.25V. The power fail output (PFO) is

active LOW but remains HIGH if PFI is above 1.25V. If this feature is

5

5

PFO

Power-fail output. PFO is active LOW whenever the PFI pin is less than

1.25V.

6

6

WDI

Watchdog input. The WDI input monitors microprocessor activity. An internal

timer is reset with each transition of the WDI input. If the WDI is held HIGH

or LOW for longer than the watchdog timeout period, typically 1.6 seconds,

140ms, minimum.

7

-

RESET

threshold or by watchdog timer timeout, RESET pulses low for the reset

threshold (4.65V in ASM690A / ASM802L and 4.4V in the ASM692A /

threshold.

-

7

RESET

Active-HIGH reset output. The inverse of RESET.

8

8

if the function is not used. The input has about 40mV of hysteresis to