Real Time Clock Serial DIE

The PCF8523 is a CMOS Real-Time Clock (RTC) and calendar optimized for low power consumption. Data is transferred serially via the I²C-bus with a maximum data rate of 1000 kbit/s. Alarm and timer functions are available with the possibility to generate a wake-up signal on an interrupt pin. An offset register allows fine-tuning of the clock. The PCF8523 has a backup battery switch-over circuit, which detects power failures and automatically switches to the battery supply when a power failure occurs.

• Provides year, month, day, weekday, hours, minutes, and seconds based on a 32.768 kHz quartz crystal
• Resolution: seconds to years
• Clock operating voltage: 1.0 V to 5.5 V
• Low backup current: typical 150 nA at V_DD = 3.0 V and T_amb = 25 °C
• 2 line bidirectional 1 MHz Fast-mode Plus (Fm+) I²C interface, read D1h, write D0h
• Battery backup input pin and switch-over circuit
• Freely programmable timer and alarm with interrupt capability
• Selectable integrated oscillator load capacitors for C_L = 7 pF or C_L = 12.5 pF
• Internal Power-On Reset (POR)
• Open-drain interrupt or clock output pins
• Programmable offset register for frequency adjustment