The DS1339U-2+ is an I2C serial real time clock (RTC) in 8 pin µSOP package. It is a low power clock/calendar with two programmable time of day alarms and programmable square wave output. Address and data are transferred serially through an I2C bus. It has operating voltage of 2V. 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 leap year compensation valid up to 2100. The clock operates in either 24hour or 12hour format with AM/PM indicator. The DS1339 has a built-in power sense circuit that detects power failures and automatically switches to the backup supply while maintaining time, date and alarm operation. It has SCL clock frequency of 400KHz in fast mode and 100KHz in standard mode. The device is used in utility meter, vending machine, thermostat, modem, router, switch and server.
● Supply voltage range from 1.8V to 5.5V
● Operating temperature range from -40°C to 85°C
● Time keeping current of 400nA and power fail voltage range from 1.58V to 1.8V
● Completely manages all timekeeping functions
● Oscillator stop flag and trickle charge capability
● Interfaces with most microcontrollers through I2C serial interface
● VCC active current of 450µA and VCC standby current of 60µA at VCC = 2.2V
● UL recognized
● Low power operation extends battery backup run time
● Automatic power fail detect and switch circuitry