AN11247
Improved timekeeping accuracy with PCF85063, PCF8523
and PCF2123 using an external temperature sensor
Rev. 1 — 17 December 2012
Application note
Document information
Info
Content
Keywords
PCF85063, PCF8523, PCF2123, RTC, accuracy, timekeeping,
temperature sensor, temperature compensation, crystal, 32.768 kHz
Abstract
The temperature dependent characteristics of quartz crystals prevent
time keeping also with state-of-the-art real time clocks from being highly
accurate over a wide temperature range, unless corrective measures are
implemented. This application note describes how the use of an external
temperature sensor, placed in a location which
will be at or near the same
temperature as the quartz crystal attached to the RTC, can improve
accuracy considerably. If the application is already using a temperature
sensor for some reason, only some extra firmware is needed without
adding to the Bill Of Material (BOM).
NXP Semiconductors
AN11247
Improved timekeeping accuracy using an external temperature sensor
AN11247_1
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© NXP B.V. 2012. All rights reserved.
Application note
Rev. 1 — 17 December 2012
2 of 16
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Revision history
Rev
Date
Description
01
20121217
Initial version, first release