2 Wire, I2C, Serial Real Time Clocks:

Real-Time Clock products offer a diverse range of real-time clock (RTC) solutions for networking and embedded applications. The primary function of RTC is to keep time and calendar data.We offer Real Time Clock (RTC) functions including Alarm RTC, Binary Counter, Real Time Calendar Clock (RTCC), Elapsed Time Recorder and Real Time Event Recorder. Use of a hardware RTC allows microcontrollers like the Raspberry Pi to be used without internet access and still provide services that use time stamps. For example, the DS1307 is a commonly available I2C based RTC module – so using the DS1307’s I2C protocol, which is supported by the Raspberry Pi, real time clock support can easily and cost-effectively be added.Another popular RTC module, also with I2C support, is the DS3231. The DS3231 is a low-cost, extremely accurate I²C real-time clock (RTC) with an integrated temperature-compensated crystal oscillator (TCXO) and crystal. The device incorporates a battery input, and maintains accurate timekeeping when mains power to the device is interrupted. Accuracy is ±2ppm from 0°C to +40°C, and ±3.5ppm from -40°C to +85°C.Apart from I2C, other interface types include 2 wire, 3 wire, 4 wire, Motorola Serial Peripheral Interface (SPI), Bytewide, Parallel, Multiplexed, and Phantom Clock.Operating temperatures range from -40°C minimum to +125°C maximum. Products are available to the AEC-Q100 Automotive Qualification Standard.