Rainbow Electronics DS3231 - Manual

General Description
The DS3231 is a low-cost, extremely accurate I 2 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.
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 I
2 C 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 reset externally.
Applications
Servers Utility Power Meters
Telematics GPS
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) I
2 C Interface
♦ 3.3V Operation
♦ Digital Temp Sensor Output: ±3°C Accuracy
♦ Register for Aging Trim
♦ RST Input/Output
♦ UL Recognized
DS3231
Extremely Accurate I
2
C-Integrated
RTC/TCXO/Crystal
______________________________________________ Maxim Integrated Products 1
Rev 2; 6/05
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
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
DS3231S+ 0°C to +70°C 16 SO DS3231+
DS3231SN+ -40°C to +85°C 16 SO DS3231N+
Pin Configuration appears at end of data sheet.
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.
DS3231
V CC
SCL
R PU
R PU = t R /C B
R PU
INT/SQW
32kHz
V BAT
PUSHBUTTON
RESET
SDA
RST
N.C.
N.C.
N.C.
N.C.
V CC
V CC
GND
V CC
CPU
N.C.
N.C.
N.C.
N.C.
Typical Operating Circuit
+Denotes lead-free