DS1339A Datasheet, PDF (1/19 Pages) Maxim Integrated Products – Low-Current, I2C, Serial Real-Time Clock

19-6425; Rev 0; 8/12
DS1339A
Low-Current, I²C, Serial Real-Time Clock
General Description
The DS1339A 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 DS1339A has a built-
in power-sense circuit that detects power failures and
automatically switches to the backup supply, maintaining
time, date, and alarm operation.
Applications
Handhelds (GPS, POS Terminals)
Consumer Electronics (Set-Top Box, Digital
Recording, Network Appliance)
Office Equipment (Fax/Printers, Copier)
Medical (Glucometer, Medicine Dispenser)
Telecommunications (Routers, Switches, Servers)
Other (Utility Meter, Vending Machine,
Thermostat, Modem)
Features
S Drop-In Replacement for DS1339
S Real-Time Clock (RTC) Counts Seconds, Minutes,
Hours, Day, Date, Month, and Year with Leap-Year
Compensation up to 2200
S I²C Serial Interface
S Two Time-of-Day Alarms
S Programmable Square-Wave Output
S Oscillator Stop Flag
S Automatic Power-Fail Detect and Switch Circuitry
S Trickle-Charge Capability
Ordering Information appears at end of data sheet.
For related parts and recommended products to use with this part,
refer to www.maxim-ic.com/DS1339A.related.
Functional Diagram
DS1339A
32.768kHz
8.192kHz
4.096kHz
X1
/4
/2
/4096 ^1Hz
MUX/
BUFFER
SQW/INTB
N
X2
VCC
VBACKUP
SCL
SDA
N
POWER CONTROL
SERIAL BUS
INTERFACE AND
ADDRESS
REGISTER
OSCILLATOR
AND
DIVIDER
CONTROL LOGIC
ALARMS,
TRICKLE CHARGER, AND
CONTROL REGISTERS
CLOCK AND
CALENDAR REGISTERS
USER BUFFER
(7 BYTES)
For pricing, delivery, and ordering information, please contact Maxim Direct
  1
at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.