DS3231 Datasheet, PDF (1/20 Pages) Dallas Semiconductor – Extremely Accurate I2C-Integrated RTC/TXO/Crystal

19-5170; Rev 7; 3/10
Extremely Accurate I²C-Integrated
RTC/TCXO/Crystal
General Description
The DS3231 is a low-cost, extremely accurate I²C 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.
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
through an I²C bidirectional bus.
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.
Applications
Servers
Telematics
Utility Power Meters
GPS
Pin Configuration appears at end of data sheet.
V_CC
SCL
SDA
μP
RST
V_CC
R_PU = t_R/C_B
R_PU
R_PU
SCL
SDA
RST
PUSHBUTTON
N.C.
RESET
N.C.
N.C.
N.C.
Features
♦ Accuracy ±2ppm from 0°C to +40°C
♦ 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
♦ Two Time-of-Day Alarms
♦ Programmable Square-Wave Output
♦ Fast (400kHz) I²C Interface
♦ 3.3V Operation
♦ Digital Temp Sensor Output: ±3°C Accuracy
♦ Register for Aging Trim
♦ RST Output/Pushbutton Reset Debounce Input
♦ Underwriters Laboratories (UL^®) Recognized
Ordering Information
PART
TEMP RANGE PIN-PACKAGE
TOP
MARK
DS3231S#
0°C to +70°C 16 SO
DS3231
DS3231SN# -40°C to +85°C 16 SO
DS3231N
#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.
Typical Operating Circuit
V_CC
V_CC
DS3231
GND
INT/SQW
32kHz
V_BAT
N.C.
N.C.
N.C.
N.C.
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.