Real-time clocks save board space

By integrating the crystal, the modules save board space, reduce cost, and improve accuracy as well as functional safety. Applications using real time clocks are much more reliable and can be more accurate compared to applications using clock crystals with 32,768kHz.

They keep track of time in all sorts of electronic equipment and are extensively used in automotive, smart meter, internet security, wireless and wireline networking, datacenter, medical, and IoT.

Epson’s RX8130CE is a cost optimised low power (300nA) RTC Module featuring a built-in power switch function optimised for rechargeable batteries and achieving an accuracy of 5 ±23 ppm at 25°C. It is designed for use of any power source including discharging battery as primary supply.

Due to the built-in power switch function no external circuits are required for the switch from primary to backup power supply in case the main supply is turned off. The RX8900CE module uses DTCXO technology to achieve ±5 or ±3.4 ppm accuracy over the entire -40 to +85°C operating range.

Its power is 700nA, which is three times lower than competing DTCXO RTCs. Epson’s DTCXO RTC technology is also available for automotive applications in the RA8900CE which is AEC-Q200 compliant and manufactured on a dedicated automotive assembly.

For the lowest applications, the RX6110SA is available. It achieves 130nA operating current and thus is ultimately suitable for any battery driven application.

All three modules include different versions of automatic power switch that requires no external components and maximizes operating life. They have an I²C interface and Epson provides a Linux driver to facilitate rapid software development.