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050200

FEATURES

Provides Real Time Clock:

-

Counts seconds, minutes, hours, date of

the month, month, day of the week, and

year with leap year compensation valid up

to 2100

-

Power control circuitry supports system

power on from day/time alarm

Microprocessor monitor:

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Halts microprocessor during power–fail

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Automatically restarts microprocessor

after power failure

-

Monitors push–button for external

override

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Halts and resets an out of control

microprocessor

=NV RAM control:

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Automatic battery backup and write

protection to external SRAM

3–channel, 8–bit analog–to–digital converter

Simple 3–wire interface

+5.0V operation

=1.25V threshold detector for power–fail

warning

PIN ASSIGNMENT

ORDERING INFORMATION

DS1677E 20–Pin TSSOP

DESCRIPTION

The Portable System Controller is a circuit which incorporates many of the functions necessary for low

power portable products integrated into one chip. The DS1677 provides a Real Time Clock, NV RAM

controller, micro-processor monitor, power–fail warning, and a 3–channel, 8–bit analog–to–digital

converter. Communication with the DS1677 is established through a simple 3–wire interface.

The Real Time Clock (RTC) provides seconds, minutes, hours, day, date, month, and year information

with leap year compensation. The RTC also provides an alarm interrupt. This interrupt works when the

DS1677 is powered by the system power supply or when in battery backup operation so the alarm can be

used to wake up a system that is powered down.

DS1677

Portable System Controller

www.dalsemi.com

20-Pin TSSOP

SCLK

I/O

CS

CEI

CEO

NC

INT

GND

ST

X1

X2

AIN0

AIN1

AIN2

RST

PFI

PFO

20

19

18

17

16

15

14

13

12

11

1

2

3

4

5

6

7

8

9

10