Systems that use microcontrollers for accurate timekeeping waste battery life, which is unacceptable in wearable applications. This approach is not the most energy-efficient, especially when small batteries power the system. The MAX31341B is designed with industry-leading power-management circuitry that remains on during dormant periods, providing timekeeping so that the microcontroller shuts down to preserve power and extend battery life. Available in an ultra-small wafer-level package measuring 2mm x 1.5mm, the RTC cuts the size by more than 35 percent to decrease the overall system design.The device operates 18 percent less than the closest competitor at under 180nA, the timekeeping current on MAX31341B allows a typical lithium coin-cell battery to last for more than 10 years in the battery backup mode. It minimizes external circuitry by incorporating features such as integrated load cap, trickle charger, power management and 64-byte RAM. Up to 100ppm (parts per million) accuracy over -40 degrees Celsius to +85 degrees Celsius based on external crystal..”

“Maxim’s real-time clock delivers accurate timekeeping while extending battery life and saving power for always-on, space- and power-constrained applications,” said Binay Bajaj, business management director for the Core Products Group at Maxim Integrated. “As the industry’s only RTC with power-management capabilities, it can offload the application processor of the timekeeping task and remain as the only device that is on when a device is not in use.”

The MAX31341B is available at Maxim’s website for $0.70 (1000-up, FOB USA); also available from authorized distributors. The MAX31341BEVKIT# evaluation kit is available for $100