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ST offers a wide portfolio of real-time clock (RTC) ICs with parallel or serial interface, including ultra-low-power devices and the world’s smallest package with embedded crystal.

Our devices offer many value-added features such as supervisory functions that include alarm, battery switchover, and reset as well as special features with time stamp, anti-tamper for secure applications and an integrated audio section.

ST's SNAPHAT® devices have a special removable/replaceable top that contains a lithium coin-cell battery and a 32-kHz crystal designed to be "snapped on" after the surface mount process. It solves the reflow compatibility of the lithium batteries and provides a solution compatible with all of ST's real-time clocks in surface-mount SOH-28 and SOH-44 packages.

All ST RTCs are Underwriters Laboratories® (UL) Recognized, see application note AN1011 "Battery technology used in NVRAM and real-time clock (RTC) products".

Design support

To make designing with real-time clock ICs even easier, ST offers two simulators:

See also our summary of development hints in application note AN3060 "Application guide for serial real-time clocks (RTCs)"

Featured Products

Real-time clock for demanding wearable devices

ST’s M41T62LC6F real-time clock is the perfect match for wearable devices when size, weight, and power-efficiency matters.

It offers a very low frequency error at 25 °C which equates to about 5 seconds per month, an ultra-low power consumption of 350 nA in standby, and comes in an ultra-small 1.5 x 3.2 mm package with an embedded crystal oscillator.