DS3231M Datasheet, PDF (1/20 Pages) Maxim Integrated Products – ±5ppm, I2C Real-Time Clock

19-5312; Rev 0; 6/10
±5ppm, I²C Real-Time Clock
General Description
The DS3231M is a low-cost, extremely accurate, I²C
real-time clock (RTC). The device incorporates a battery
input and maintains accurate timekeeping when main
power to the device is interrupted. The integration of
the microelectromechanical systems (MEMS) resona-
tor enhances the long-term accuracy of the device and
reduces the piece-part count in a manufacturing line.
The DS3231M is available in the same footprint as the
popular DS3231 RTC.
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 1Hz output are provided. Address and
data are transferred serially through an I²C bidirectional
bus. A precision temperature-compensated voltage
reference and comparator circuit monitors the status of
VCC to detect power failures, to provide a reset output,
and to automatically switch to the backup supply when
necessary. Additionally, the RST pin is monitored as a
pushbutton input for generating a microprocessor reset.
See the Block Diagram for more details.
Power Meters
Industrial Applications
Applications
Ordering Information
PART
DS3231MZ+*
DS3231M+
TEMP RANGE
-40NC to +85NC
-40NC to +85NC
PIN-PACKAGE
8 SO
16 SO
+Denotes a lead(Pb)-free/RoHS-compliant package.
*Future product—contact factory for availability.
Features
S Timekeeping Accuracy Q5ppm (Q0.432 Second/
Day) from -40NC to +85NC
S Battery Backup for Continuous Timekeeping
S Low Power Consumption
S Footprint and Functionally Compatible to DS3231
S Complete Clock Calendar Functionality Including
Seconds, Minutes, Hours, Day, Date, Month, and
Year with Leap Year Compensation Up to Year
2100
S Two Time-of-Day Alarms
S 1Hz and 32.768kHz Outputs
S Reset Output and Pushbutton Input with
Debounce
S Fast (400kHz) I²C-Compatible Serial Bus
S +2.3V to +5.5V Supply Voltage
S Digital Temp Sensor with Q3NC Accuracy
S -40NC to +85NC Temperature Range
S 16-Pin SO (300 mils) Package
S Underwriters Laboratories (UL) Recognized
Typical Operating Circuit
+3.3V
+3.3V
I/O PORT
INTERRUPTS
CPU
SCL
SDA
32KHZ
VBAT
INT/SQW
RST
DS3231M
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.
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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.