Rainbow Electronics DS1338 - Manual

1 of 15 REV: 091404
Note: Some revisions of this device may incorporate deviations from published specifications known as errata. Multiple revisions of any device
may be simultaneously available through various sales channels. For information about device errata, go to:
www.maxim-ic.com/errata .
GENERAL DESCRIPTION
The DS1338 serial real-time clock (RTC) is a low-
power, full binary-coded decimal (BCD)
clock/calendar plus 56 bytes of NV SRAM. Address
and data are transferred serially through an I
2 C™
interface. The clock/calendar provides seconds,
minutes, hours, day, date, month, and year
information. The end of the month date 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 DS1338 has a built-in power-
sense circuit that detects power failures and
automatically switches to the battery supply.
APPLICATIONS
Handhelds (GPS, POS Terminal)
Consumer Electronics (Set-Top Box, Digital
Recording, Network Appliance)
Office Equipment (Fax/Printer, Copier)
Medical (Glucometer, Medicine Dispenser)
Telecommunications (Router, Switcher, Server)
Other (Utility Meter, Vending Machine, Thermostat,
Modem)
TYPICAL OPERATING CIRCUIT
FEATURES
§ RTC Counts Seconds, Minutes, Hours, Date of
the Month, Month, Day of the Week, and Year
with Leap-Year Compensation Valid Up to 2100
§ Available in a Surface-Mount Package with an
Integrated Crystal (DS1338C)
§ 56-Byte Battery-Backed NV RAM for Data
Storage
§ I 2 C Serial Interface
§ Programmable Square-Wave Output Signal
§ Automatic Power-Fail Detect and Switch Circuitry
§ Underwriters Laboratory (UL) Recognized
ORDERING INFORMATION
PART TEMP RANGE PIN-PACKAGE TOP MARK
DS1338Z-18 -40°C to +85°C 8 SO (150 mils) DS1338-18
DS1338Z-3 -40°C to +85°C 8 SO (150 mils) DS1338-3
DS1338Z-33 -40°C to +85°C 8 SO (150 mils) DS1338-33
DS1338U-18 -40°C to +85°C 8 mSOP
1338
rr-18
DS1338U-3 -40°C to +85°C 8 mSOP
1338
rr-3
DS1338U-33 -40°C to +85°C 8 mSOP
1338
rr-33
DS1338C-18 -40°C to +85°C 16 SO (300 mils) DS1338C-18
DS1338C-3 -40°C to +85°C 16 SO (300 mils) DS1338C-3
DS1338C-33 -40°C to +85°C 16 SO (300 mils) DS1338C-33
rr = second line, revision level
Pin Configurations appear at end of data sheet.
DS1338
I
2
C RTC with 56-Byte NV RAM
www.maxim-ic.com
I 2 C is a trademark of Philips Corp. Purchase of I 2 C components from
Maxim Integrated Products, Inc., or one of its sublicensed Associated
Companies, conveys a license under the Philips I
2 C Patent Rights to
use these components in an I 2 C system, provided that the system
conforms to the I 2 C Standard Specification as defined by Philips.
DS1338
CPU
V
CC
V
CC
V
CC
SDA
SCL
GND
X2 X1
V
CC
RPU RPU
CRYSTAL
SQW/OUT
V
BAT
i
RPU = t
R
/ C
B