The DS1340U-3+ is an I2C real time clock (RTC) with trickle charger in 8 pin µSOP package. The device additionally provides trickle-charge capability on the VBACKUP pin, a lower timekeeping voltage and an oscillator STOP flag. The RTC/calendar is pin compatible and functionally equivalent to the ST M41T00, including the software clock calibration. Block access of the register map is identical to the ST device. Two additional registers which are accessed individually are required for the trickle charger and flag. The clock/calendar provides seconds, minutes, hours, day, date, month and year information. A built-in power-sense circuit detects power failures and automatically switches to the backup supply. Reads and writes are inhibited while the clock continues to run. The device is programmed serially through an I2C bidirectional bus. It is used in point of sale equipment and telecommunications.
● Supply voltage range is 2.7V to 5.5V
● Operating temperature range from -40°C to 85°C
● Enhanced second source for the ST M41T00
● Completely manages all timekeeping functions
● Low power operation extends battery backup run time
● Low timekeeping voltage down to 1.3V
● Automatic power-fail detect and switch circuitry, supports systems using legacy & modern power buses
● Simple serial port interfaces with most microcontrollers, fast 400KHz I2C interface
● Minimizes space required
● UL recognized
