Rev 3; 10/07
2
Extremely Accurate I C RTC with
Integrated Crystal and SRAM
DS32
General Description
Features
♦ Accuracy 2ppm from 0°C to +40°C
The DS3232 is a low-cost temperature-compensated
crystal oscillator (TCXO) with a very accurate, tempera-
ture-compensated, integrated real-time clock (RTC) and
236 bytes of battery-backed SRAM. Additionally, the
DS3232 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 DS3232
is available in commercial and industrial temperature
ranges, and is offered in an industry-standard 20-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
♦ 236 Bytes of Battery-Backed SRAM
♦ Low-Power Consumption
♦ Real-Time Clock Counts Seconds, Minutes,
Hours, Day, Date, Month, and Year with Leap Year
Compensation Valid Up to 2099
♦ Two Time-of-Day Alarms
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.
♦ 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 Input/Output
♦ 300-Mil, 20-Pin SO Package
®
♦ Underwriters Laboratories (UL ) Recognized
A precision temperature-compensated voltage refer-
Ordering Information
ence and comparator circuit monitors the status of V
CC
PIN-
PACKAGE
TOP
MARK
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.
PART
TEMP RANGE
DS3232S#
0°C to +70°C
20 SO
20 SO
DS3232
DS3232SN#
-40°C to +85°C
DS3232N
# Denotes a RoHS-compliant device that may include lead that
is exempt under the RoHS requirements. 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.
Applications
Utility Power Meters
GPS
Servers
Telematics
Typical Operating Circuit
Pin Configuration
TOP VIEW
V
V
CC
CC
R
PU
= t / C
R B
N.C.
N.C.
1
2
3
4
5
6
7
8
9
20 SCL
19 N.C.
18 SCL
17 SDA
V
CC
R
PU
R
PU
V
32kHz
CC
SCL
SDA
RST
N.C.
INT/SQW
32kHz
V
CC
CPU
INT/SQW
RST
16 V
BAT
DS3232
V
BAT
PUSH-
BUTTON
RESET
15 GND
N.C.
N.C.
N.C.
N.C.
N.C.
N.C.
N.C.
N.C.
N.C.
14
DS3232
N.C.
N.C.
13 N.C.
12 N.C.
11 N.C.
N.C.
N.C.
N.C.
GND
N.C. 10
SO
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.