Epson RTC-72421 A Manuel D’Utilisation

RTC - 72421 / 72423 

 

 

 

 

 

 
 

CONTENTS 

 
 

„ Overview ............................................................................................. 1

 

„ Block diagram ..................................................................................... 1

 

„ Terminal connections .......................................................................... 2

 

„ Terminal functions............................................................................... 3

 

„ Characteristics .................................................................................... 4

 

1. Absolute maximum ratings........................................................................................ 4

 

2. Recommended operating conditions ......................................................................... 4

 

3. Frequency characteristics and current consumption characteristics.......................... 4

 

4. Electrical characteristics ( DC characteristics ) ......................................................... 4

 

„ Switching characteristics 

(AC characteristics)

........................................... 5

 

1. When ALE is used .................................................................................................... 5

 

2. When ALE is fixed at V

DD

......................................................................................... 6

 

„ Registers............................................................................................. 7

 

1. Register table............................................................................................................ 7

 

2. Notes ........................................................................................................................ 7

 

3. Functions of register bits (overview).......................................................................... 7

 

4. Setting the fixed-period pulse output mode and fixed-period interrupt mode............. 8

 

5. Resetting the fixed-period pulse output mode and fixed-period interrupt mode......... 8

 

„ Register description ............................................................................ 9

 

1. Timing registers ........................................................................................................ 9

 

2. CD register (control register D) ............................................................................... 10

 

3. CE register (control register E)................................................................................ 11

 

4. CF register (control register F) ................................................................................ 13

 

„ Using the RTC-72421/RTC-72423 .....................................................14

 

1. Power-on procedure (initialization) .......................................................................... 14

 

2. Read/write of S1 to W registers .............................................................................. 16

 

3. Write to 30-second ADJ bit ..................................................................................... 16

 

4. Using the CS

1

 pin ................................................................................................... 17

 

„ Power supply circuit example.............................................................17

 

„ Examples of connection to general-purpose microprocessor .............18

 

„ External dimensions...........................................................................19

 

„ Marking layout....................................................................................19

 

„ Reference data ..................................................................................20

 

„ Application notes................................................................................21

 

1. Notes on handling ................................................................................................... 21

 

2. Notes on packaging ................................................................................................ 21