Contact information, Revision history | NXP Semiconductors PCA8565

NXP Semiconductors

UM10301

Revision history

Rev Date

01 20081223

User Manual PCF85x3, PCA8565 and PCF2123, PCA2125

Description

Initial version.

This application note / user manual is a complete update of a previous publication titled: “Application note for the Philips Real Time Clocks PCF8563,73,83,93” which did not have an official AN/UM number and is superseded by this document.

The contents were revised with lots of additional information added and errors in the examples corrected. Additionally it includes information with respect to recently introduced RTCs.

Contact information

For additional information, please visit: http://www.nxp.com

For sales office addresses, please send an email to: salesaddresses@nxp.com

UM10301_1		© NXP B.V. 2008. All rights reserved.
User manual	Rev. 01 — 23 December 2008	2 of 52

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NXP Semiconductors PCA8565, PCF85x3 Contact information, NXP Semiconductors, Revision history, Rev Date Description

Contents

Abstract Info Content KeywordsDocument information Revision history Contact informationNXP Semiconductors Rev Date Description Introduction Features Register overview PCF8563 Address Register name Bit Event counter mode Comparison Features Comparison of six real time clocks Voltage-low detector Power-on reset PORPower-on reset Oscillator-stop detection OscillatorVoltage-low detection Pierce Oscillator equivalent diagram Overview of internal and external oscillator capacitors Oscillator frequency determining components UM10301 + C Typical values for crystal and surrounding capacitors Parameter Value Unit Source Using an external oscillator Oscillation allowance Crystal and crystal selection Effect of temperature Modes which don’t work − f nom Capacitors and capacitor selection Accuracy Influences on time accuracy Oscillator tuning Oscillator tuning 10.1 PCF2123 Offset register Year and leap year tracking Century and leap year, Daylight Saving TimeCentury tracking Daylight Saving Time DST Block Diagram PCF8563 Initialization and setting of alarm and timerInitialization of the RTC and setting the time Binary BCD AlarmSetting the alarm Register Comments Address Alarm function Register Setting the timerSetting the timer Backup power supply Lithium Primary cells Backup circuit using primary lithium cell Backup circuit using secondary cell NiCd or NiMH NiCd and NiMH secondary batteries 13.3 Capacitors Charging the backup capacitor 1N4148 Diode selectionSome suggestions for diode D1 BAS716 BAS116 BAV170 PCB layout guidelines PCB layout proposal for PCF8563 using leaded components Partial circuit switch down Hints to keep power consumption low Protection diodes 0007 8473 ⋅ C b Rpmax as a function of bus capacitance Application diagram 1, I2C-bus interface Application diagram 2, SPI interface Timer Source clock frequency Delay for n = First period inaccuracy when using the timerTimer delays General countdown timer behaviour First period delay for timer counter value n Timer source clock Minimum timer period Maximum timer period Timing requirements for I2C read and write Block diagram I2C interface and Time counters I2C interface Sequence of events example Read Troubleshooting Oscillator startup time Checking for oscillation No communication via I2C-bus References Wrong time and date, wrong clock speed Disclaimers Legal informationDefinitions Trademarks Contents