RX8111CE/RX4111CE Real-Time Clocks

Epson RX8111CE and RX4111CE real-time clock (RTC) modules integrate a 32.768 kHz crystal into the package, saving PCB space and eliminating the need to design an external oscillator circuit. Both come in a compact 3.2 mm x 2.5 mm package.

The RX8111CE and RX4111CE provide ultra-low power consumption both at component and system level. As standalone components, these RTCs consume very low power utilizing Epson’s low ESR crystals and in-house IC design and manufacturing. On the system level, the RX8111CE and RX4111CE allow users to power down their system and switch to backup battery operation where these components only consume 100 nA typical while still keeping time. Backup power mode can be automatically enabled via auto power switching when V_DD falls below operation levels.

Additional features include wakeup timer, time stamping, selectable output frequency, alarm, and self-monitoring (crystal oscillation, V_DD low, and V_BAT low). The RX4111CE uses SPI, while the RX8111CE uses I²C interface.