Real_Time Clock (RTC for short) mainly provides time reference for various electronic systems. Generally, the RTC integrated inside the chip is called the in-chip RTC, and the RTC expanded outside the chip is called the external RTC.
The development of RTC
Early RTC often used 74/54 series, CC4000 series and 555 integrated circuit to build a second pulse source, and then used frequency divider, counter, cache, etc. to get the timing signals of minutes, hours, days, months and years, and finally sent to the processor through the communication port for processing. Due to the complexity of circuit setup and the great influence of device characteristics, such RTC often has poor accuracy, high power consumption and occupies a large area of PCB space.
In the latest generation of RTC products, in addition to all the functions of the second generation products, composite functions are added, such as low voltage detection, primary standby battery switching function, anti-pcb leakage function, and the package itself is smaller (height: 0.85mm, area: 2mm*2mm).
