DS3232 pdf datasheet (Extremel

The DS3232 is a low-cost temperature-compensated
crystal oscillator (TCXO) with a very accurate, temperature-
compensated, integrated real-time clock (RTC) and
236 bytes of battery-backed SRAM. Additionally, the
DS3232 incorporates a battery input and maintains accurate
timekeeping when main power to the device is interrupted.
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.
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-ofday
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 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 μP reset.
Applications
Servers Utility Power Meters
Telematics GPS