General Description
The DS1341/DS1342 low-current real-time clocks (RTCs) are  timekeeping  devices  that  provide  an  extremely  low standby current, which permits longer life from a power supply. The DS1341/DS1342 support high-ESR crystals, which broaden the pool of usable crystals for the devices. The DS1341 uses a 6pF crystal, while the DS1342 uses a 12.5pF crystal. These devices are accessed through an I2C serial interface. Other features include two time-of-day alarms,  two  interrupt  outputs,  a  programmable  square wave output, and a serial bus timeout mechanism.
The  clock/calendar  provides  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  24hr  or  12hr  format
with an AM/PM indicator.

Features
Low Timekeeping Current of 250nA (typ)
Compatible with Crystal ESR Up to 80kI
Use Crystals with CL= 6pF (DS1341) or CL= 12.5pF (DS1342)
+1.8V to +5.5V Operating Voltage Range
Maintain Time Down to +1.15V (typ)
Fast (400kHz) I2C Interface
Bus Timeout for Lockup-Free Operation
RTC Counts Seconds, Minutes, Hours, Day, Date, Month, and Year with Leap Year Compensation
Valid Through 2099
External Clock Source for Synchronization Clock Reference (e.g., 32kHz, 50Hz/60Hz Power Line,
GPS 1PPS)
Two Time-of-Day Alarms with Two Interrupt Outputs
Programmable Square-Wave Output
Industrial Temperature Range
Small, 8-Pin µSOP Package

APPLICATIONs
Medical
Point of Sale (POS)
Telematics
Portable Instruments
Portable Audio
Automotive