TI PCA9544A Multiplexer Specs

• I²C Bus 
• Four Active-Low Interrupt Inputs
• Active-Low Interrupt Output
• Three Address Pins 

DS1339 I²C Serial Real-Time Clock (RTC)

• Manages all Timekeeping functions: Counts Seconds, Minutes, Hours, Date of the Month, Month, Day of the Week, and Year with Leap-Year Compensation Valid Up to 2100
• Two Time-of-Day alarms

Power Requirements

• Voltage: 3.0V - 5.5V 

Pins Used

• A5/SCL - I²C Serial Clock line
• A4/SDA - I²C Serial Data line
• IO2 - Used for RTC
• IO3 - Used for RTC
• IO4 - Power Control 

Dimensions

• 53.34mm x 57.58mm (2.1 inches x 2.27 inches)
• Max Height: 12.5mm (0.48 inches) Measured from the top of the 5-pin connectors, and the bottom of soldered header pins
• Weight: 10g (.35 ounces)