•Built in frequency adjusted 32.768 kHz crystal unit.
•Interface Type : SPI & I2C -Bus
•Operating voltage range : 1.6 V to 5.5 V
•The wide voltage for time keeping. : 1.1 V to 5.5 V
•Low backup current : 130 nA / 3 V ( Typ. )
•Built-in user RAM : 128 bit ( 8 bit × 16, SRAM)
•Auto power switching functions : When VDD deteriorates
than 1.6V, internal source is switched to VBAT.