Epson RTC-72421 - Page 4

CONTENTS
■ Using the RTC-72421/RTC-72423 ----------------------------------------------------------------16
1. Power-on procedure (initialization) ------------------------------------------------------------------------------------16
2. Read/write of S1 to W registers-----------------------------------------------------------------------------------------18
3. Write to 30-second ADJ bit ----------------------------------------------------------------------------------------------18
4. Using the CS1 pin ----------------------------------------------------------------------------------------------------------19
(1) Functions-----------------------------------------------------------------------------------------------------------------19
(2) Timing---------------------------------------------------------------------------------------------------------------------19
(3) Note-----------------------------------------------------------------------------------------------------------------------19
■ Power supply circuit example-----------------------------------------------------------------------19
■ Examples of connection to general-purpose microprocessor ------------------------------20
1. Connection to multiplexed bus type ------------------------------------------------------------------------------------20
2. Connection to Z80 or compatible CPU --------------------------------------------------------------------------------20
3. Connection to 68-series MPU--------------------------------------------------------------------------------------------20
■ Reference data -----------------------------------------------------------------------------------------21
1. Frequency temperature characteristics (typical) --------------------------------------------------------------------21
2. Frequency voltage characteristics (typical)---------------------------------------------------------------------------21
3. Current consumption voltage characteristics (typical) -------------------------------------------------------------21
■ External dimensions-----------------------------------------------------------------------------------22
1. RTC-72421 -------------------------------------------------------------------------------------------------------------------22
2. RTC-72423 -------------------------------------------------------------------------------------------------------------------22
■ Marking layout ------------------------------------------------------------------------------------------22
■ Application notes---------------------------------------------------------------------------------------23
1. Notes on handling----------------------------------------------------------------------------------------------------------23
(1) Static electricity ---------------------------------------------------------------------------------------------------------22
(2) Noise ----------------------------------------------------------------------------------------------------------------------22
(3) Voltage levels of input pins ------------------------------------------------------------------------------------------22
(4) Treatment of unused input pins-------------------------------------------------------------------------------------22
2. Notes on mounting---------------------------------------------------------------------------------------------------------23
(1) Soldering temperature conditions----------------------------------------------------------------------------------23
(2) Mounting equipment---------------------------------------------------------------------------------------------------24
(3) Ultrasonic cleaning-----------------------------------------------------------------------------------------------------24
(4) Mounting orientation---------------------------------------------------------------------------------------------------24
(5) Leakage between pins------------------------------------------------------------------------------------------------24