ASM690A/692A, ASM802L/802M, ASM805L

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2

Figure 1. Typical Operating Circuit

Figure 2. Block Diagram

Table 1. PIN DESCRIPTION

Pin Number

Name

Function

ASM690A/ASM692A

ASM802L/ASM802M

ASM805L

1

1

higher) through the MOS switch to provide continuous power to the CMOS RAM.

2

2

+5 V power supply input.

3

3

GND

Ground.

4

4

PFI

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

or which is referenced to 1.25 V. The power fail output (PFO) is active LOW but

remains HIGH if PFI is above 1.25 V. If this feature is unused, the PFI pin should

5

5

PFO

Power−fail output. PFO is active LOW whenever the PFI pin is less than 1.25 V.

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, RESET

7

−

RESET

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

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

−

7

RESET

Active−HIGH reset output. The inverse of RESET.

8

8

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