DATASHEET
REAL-TIME CLOCK WITH I
2
C SERIAL INTERFACE IDT1337AG
IDT®
REAL-TIME CLOCK WITH I
2
C SERIAL INTERFACE 1
IDT1337AG REV C 011514
General Description
The IDT1337AG device is a low power serial real-time clock
(RTC) device with two programmable time-of-day alarms
and a programmable square-wave output. Address and
data are transferred serially through an I
2
C bus. The device
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.
Applications
• Telecommunication (Routers, Switches, Servers)
• Handhelds (GPS, POS terminals, MP3 players)
• Set-Top Box, Digital Recording,
• Office (Fax/Printers, Copiers)
• Medical (Glucometer, Medicine Dispensers)
• Other (Thermostats, Vending Machines, Modems, Utility
Meters, Digital Photo Frame devices)
Features
• Real-Time Clock (RTC) counts seconds, minutes, hours,
day, date, month, and year with leap-year compensation
valid up to 2100
• Packaged in 8-pin MSOP, 8-pin SOIC, or 16-pin SOIC
(surface-mount package with an integrated crystal)
• I
2
C Serial interface (Normal and Fast modes)
• Two time-of-day alarms
• Oscillator Stop Flag
• Programmable square-wave output defaults to 32 kHz on
power-up
• Operating voltage of 1.8 to 5.5 V
• Industrial temperature range (-40 to +85°C)
Block Diagram
SCL
SDA
Crystal inside package
for 16-pin SOIC ONLY
X1
X2
1 Hz/4.096 kHz/
8.192 kHz/32.768 kHz
SQW/INTB
I
2
C
Interface
32.768 kHz
Oscillator and
Divider
Control
Logic
MUX/
Buffer
Clock,
Calendar
Counter
1 Byte
Control
7 Bytes
Buffer
Alarm
Registers
INTA
VCC
GND
