19-5170; Rev 7; 3/10
2
Extremely Accurate I C-Integrated
RTC/TCXO/Crystal
DS231
General Description
Features
2
♦ Accuracy 2ppm from 0°C to +40°C
The DS3231 is a low-cost, extremely accurate I C real-
time clock (RTC) with an integrated temperature-
compensated crystal oscillator (TCXO) and crystal. The
device incorporates a battery input, and maintains accu-
rate timekeeping when main power to the device is inter-
rupted. The integration of the crystal resonator enhances
the long-term accuracy of the device as well as reduces
the piece-part count in a manufacturing line. The DS3231
is available in commercial and industrial temperature
ranges, and is offered in a 16-pin, 300-mil SO package.
♦ Accuracy 3.5ppm from -40°C to +85°C
♦ Battery Backup Input for Continuous
Timekeeping
♦ Operating Temperature Ranges
Commercial: 0°C to +70°C
Industrial: -40°C to +85°C
♦ Low-Power Consumption
♦ Real-Time Clock Counts Seconds, Minutes,
Hours, Day, Date, Month, and Year with Leap Year
Compensation Valid Up to 2100
The RTC maintains 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 an AM/PM indicator. Two programmable time-of-
day alarms and a programmable square-wave output
are provided. Address and data are transferred serially
♦ Two Time-of-Day Alarms
♦ Programmable Square-Wave Output
2
♦ Fast (400kHz) I C Interface
♦ 3.3V Operation
♦ Digital Temp Sensor Output: 3°C Accuracy
♦ Register for Aging Trim
♦ RST Output/Pushbutton Reset Debounce Input
2
through an I C bidirectional bus.
®
♦ Underwriters Laboratories (UL ) Recognized
A precision temperature-compensated voltage refer-
ence and comparator circuit monitors the status of V
CC
to detect power failures, to provide a reset output, and
to automatically switch to the backup supply when nec-
essary. Additionally, the RST pin is monitored as a
pushbutton input for generating a µP reset.
Ordering Information
TOP
PART
TEMP RANGE PIN-PACKAGE
MARK
DS3231
DS3231N
DS3231S#
0°C to +70°C 16 SO
DS3231SN# -40°C to +85°C 16 SO
Applications
Utility Power Meters
#Denotes a RoHS-compliant device that may include lead that
is exempt under RoHS requirements. The lead finish is JESD97
category e3, and is compatible with both lead-based and lead-
free soldering processes. A "#" anywhere on the top mark
denotes a RoHS-compliant device.
Servers
Telematics
GPS
Pin Configuration appears at end of data sheet.
Typical Operating Circuit
V
CC
V
CC
R
PU
= t /C
R B
V
CC
R
R
PU
PU
V
CC
SCL
SDA
INT/SQW
32kHz
SCL
SDA
μP
V
BAT
RST
RST
DS3231
PUSHBUTTON
RESET
N.C.
N.C.
N.C.
N.C.
N.C.
N.C.
N.C.
N.C.
GND
UL is a registered trademark of Underwriters Laboratories, Inc.
______________________________________________ Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.