Features 

• 2.0 to 5.5v clock operating voltage
• Counters for tenths/hundredths of seconds, seconds, minutes, hours, day, date, month, year, and century 
• Automatic switch-over and deselect circuitry 
• Serial interface supports i2c bus (400khz protocol) 
• Programmable alarm and interrupt function (valid even during battery back-up mode) 
• Watchdog timer 
• Low operating current of 400µa
• Battery back-up not recommended for 3.0v applications (capacitor back-up only)
• Battery or super-cap back-up 
• Operating temperature of –40 to 85°c
• Ultra-low battery supply current of 1µa 
• Package options include a 28-lead or 18-lead embedded crystal soic