MAX31343 Real-Time Clock (RTC) Analog Devices MAX31343 Real-Time Clock (RTC) is a low-cost, extremely accurate, I2C RTC. The device incorporates a battery input and maintains accurate timekeeping when the main power to the device is interrupted. The integration of the microelectromechanical systems (MEMS) resonator enhances the long-term accuracy of the device and eliminates the external crystal requirement in the system. The MAX31343 is available in the 8-pin WLP and TDFN packages.