What’s immediately obvious about RTC4 click is the coin cell 1F supercapacitor that will enable the click to keep time for years on end.
Under the supercapacitor is the DS2417 IC, a real time clock/calendar from Maxim. What’s different about it compared to preceding RTC clicks, is that this one communicates with the target MCU through a 1-Wire interface; but it also has a programmable interrupt for system wakeup on a separate pin.
Since it’s a 1-Wire device, it has a factory lasered and tested 64-bit registration number, allowing it to function within a MicroLAN network (a network of 1-Wire devices that are all associated with a master device).
Why four real time clock clicks, you might ask?
Maybe it’s not shiny new tech, but RTC chips are silent workhorses that, by keeping time, make a lot of other things possible. Once you incorporate one in your design, it’ll blend in and do its work for a long time. It’s important to give you the option to choose exactly the one you need for your project.