You are here

AN53313 - Real Time Clock Calibration in Cypress nvSRAM | Cypress Semiconductor

AN53313 - Real Time Clock Calibration in Cypress nvSRAM

최신 업데이트: 
2020년 5월 28일
버전: 
*E

AN53313 describes the Real Time Clock (RTC) calibration feature in Cypress nvSRAM that helps to maintain precise system time by compensating for the crystal frequency error.

개요

The Real Time Clock (RTC) in Cypress nvSRAM is driven by a crystal oscillator, with an external crystal having a nominal frequency of 32.768 kHz. Most 32.768-kHz crystals have a frequency tolerance of ±20 parts per million (ppm) at +25 °C. This frequency tolerance results in timing error over a long period of time. For example, a crystal with 20-ppm error in nominal frequency can drift the clock accuracy by 52 seconds in a month. You can compensate this drift by using  the calibration feature in the nvSRAM RTC.

 

Calibration Circuit Block Diagram

번역 문서는 참고용으로만 제공하는 것입니다. 설계 과정에 참여할 경우에는 영어 버전 문서를 참고하는 것이 좋습니다.