ROHM BU9873F-GTE2, Real Time Clock (RTC) Serial-I2C, 8-Pin SOP

The BU9873 is a CMOS real-time clock, which has a built-in interrupt generation function. This product is connected to the CPU via I²C interface, and configured to perform serial transmission of time and calendar data to the CPU. A high-precision oscillation adjustment circuit is also integrated, which is capable of adjusting time counts with digital method, and correcting deviations in the oscillation frequency of the crystal oscillator.

Connected to the CPU via I²C Interface
Time (Hour･Minute･Second, Selectable 12-Hour and 24-Hour Mode Setting)
Calendar (Year･Month･Day･Week)
Periodic Interrupt Function (Output from INTRB, Ranging from 1 Second to 1 Month)
Alarm Interrupt Function (Day-of-Week･Hour･Minute in Setting Format, Output from INTRB)
Oscillation Halt Sensing Function
±30 Second Adjustment Function
Automatic Leap Year Recognition up to the Year 2099