The PCF85163 is a CMOS 1 Real-Time Clock (RTC) and calendar engineered for minimal power consumption. It offers versatile functionality, featuring a programmable clock output, interrupt output, and voltage-low detector. Utilizing a two-line bidirectional I2C bus for serial communication, it supports a maximum bus speed of 400 kbit/s. The register address automatically increments after each data byte transfer. This RTC provides accurate timekeeping with year, month, day, weekday, hours, minutes, and seconds based on a 32.768 kHz quartz crystal. Additional features include a century flag, a wide operating voltage range (1.8 V to 5.5 V), a low backup current (0.25 μA typical), alarm and timer functions, and an internal Power-On Reset (POR). With a programmable clock output for peripheral devices and an open-drain interrupt pin, the PCF85163 is a versatile solution for various applications requiring precise timekeeping in space-constrained designs.