DATASHEET
REAL-TIME CLOCK WITH BATTERY BACKED NON-VOLATILE RAM
General Description
The IDT1338 is a serial real-time clock (RTC) device that
consumes ultra-low power and provides a full binary-coded
decimal (BCD) clock/calendar with 56 bytes of battery
backed Non-Volatile Static RAM. The clock/calendar
provides seconds, minutes, hours, day, date, month, and
year information. The clock operates in either the 24-hour
or 12-hour format with AM/PM indicator. The end of the
month date is automatically adjusted for months with fewer
than 31 days, including corrections for leap year. Access to
the clock/calendar registers is provided by an I
2
C interface
capable of operating in fast I
2
C mode. Built-in Power-sense
circuitry detects power failures and automatically switches
to the backup supply, maintaining time and date operation.
IDT1338
Features
•
Real-Time Clock (RTC) counts seconds, minutes, hours,
day, date, month, and year with leap-year compensation
valid up to 2100
•
56-Byte battery-backed Non Volatile RAM for data
storage
•
•
•
•
Fast mode I
2
C Serial interface
Automatic power-fail detect and switch circuitry
Programmable square-wave output
Packaged in 8-pin MSOP, 8-pin SOIC, or 16-pin SOIC
(surface-mount package with an integrated crystal)
•
Industrial temperature range (-40°C to +85°C)
Applications
•
Telecom (Routers, Switches, Servers)
•
Handheld (GPS, Point of Sale POS terminals)
•
Consumer Electronics (Set-Top Box, Digital Recording,
Network Applications, Digital photo frames)
•
Office (Fax/Printers, Copiers)
•
Medical (Glucometer, Medicine Dispensers)
•
Others (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
32.768 kHz
Oscillator and
Divider
MUX/
Buffer
SQW/OUT
X2
VCC
GND
V
BAT
Power
Control
Control
Logic
Clock, Calendar
Counter
SCL
SDA
I
2
C
Interface
56 Byte
RAM
1 Byte
Control
7 Bytes
Buffer
IDT®
REAL-TIME CLOCK WITH BATTERY BACKED NON-VOLATILE RAM 1
IDT1338
REV K 032910
IDT [ INTEGRATED DEVICE TECHNOLOGY ]
