August 2007

Rev 1

1/14

AN2604

Application note

STM32F101xx and STM32F103xx RTC calibration

Introduction

The real-time clock (RTC) precision is a requirement in most embedded applications, but

due to external environment – temperature change, frequency variation of the crystal that

clocks the RTC – the RTC precision may not be as accurate as expected.

The RTC embedded in the STM32F101xx and STM32F103xx comes with a digital clock

calibration circuit suitable for manufacturing environments, that allows applications to

compensate for crystal and temperature variations. This application note discusses the RTC

calibration basics and explains how RTC calibration can be used to improve timekeeping

accuracy.

www.st.com