Rainbow Electronics DS1677 - Manual

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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:
- Halts microprocessor during power–fail
- Automatically restarts microprocessor
after power failure
- Monitors push–button for external
override
- Halts and resets an out of control
microprocessor
=NV RAM control:
- 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
V
BAT
V
CCO
SCLK
I/O
CS
CEI
CEO
NC
INT
GND
ST
V
CC
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