DATASHEET
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REAL-TIME CLOCK WITH SERIAL I C INTERFACE
IDT1339
General Description
Features
The IDT1339 serial real-time clock (RTC) is a low-power
clock/date device with two programmable time-of-day
alarms and a programmable square-wave output. Address
and data are transferred serially through an I2C bus. The
clock/date provides seconds, minutes, hours, day, date,
month, and year information. The date at the end of the
month is automatically adjusted for months with fewer than
31 days, including corrections for leap year. The clock
operates in either the 24-hour or 12-hour format with
AM/PM indicator. The IDT1339 has a built-in power-sense
circuit that detects power failures and automatically
switches to the backup supply, maintaining time, date, and
alarm operation.
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Real-Time Clock (RTC) counts seconds, minutes, hours,
day, date, month, and year with leap-year compensation
valid up to 2100
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Packaged in 8-pin MSOP, 8-pin SOIC, or 16-pin SOIC
(surface-mount package with an integrated crystal)
Fast mode I2C Serial interface
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Two time-of-day alarms
Programmable square-wave output
Oscillator stop flag
Automatic power-fail detect and switch circuitry
Trickle-charge capability
Applications
Industrial temperature range (-40 to +85°C)
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Handhelds (GPS, POS terminals)
Consumer Electronics (Set-Top Box, Digital Recording,
Network Applications)
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Office (Fax/Printers, Copiers)
Medical (Glucometer, Medicine Dispensers)
Telecomm (Routers, Switches, Servers)
Other (Thermostats, Vending Machines, Modems, Utility
Meters)
Block Diagram
Crystal inside package
for 16-pin SOIC ONLY
1 Hz/4.096 kHz/
8.192 kHz/32.768 kHz
X1
X2
MUX/
Buffer
32.768 kHz
Oscillator and
Divider
SQW/INT
GND
VCC
Clock,
Calendar
Counter
Control
Logic
Power
Control
Trickle
Charger
VBACKUP
SCL
SDA
I2C
Interface
1 Byte 7 Bytes 7 Bytes 1 Byte
Control Buffer Alarm Status
IDT® REAL-TIME CLOCK WITH SERIAL I2C INTERFACE
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IDT1339
REV K 032910
IDT [ INTEGRATED DEVICE TECHNOLOGY ]
