By extending the two-digit year to four digits with the addition of a century counter, the RTC8563 real-time clock module offers system Y2K compliance. The device, which features a built-in 32.768-kHz crystal, transmits address and data serially by means of a two-line, bi-directional, I2C bus. Optimized for low power consumption, the clock module is capable of operating at supply voltages as low as 1.8V with typical backup current of 0.25 µA at 2V. Other features include available alarm and timer functions. Operating voltage range is from 1.8V to 5.5V and data-hold voltage range is from 1V to 5.5V. Package options include a 14-pin SOP or a low-profile, 20-pin VSOJ.