Digital Line to POTS Interface

CMX615

© 1999 Consumer Microcircuits Limited

2

D/615/4

CONTENTS

Section

Page

1.1 Brief Description.........................................................................................1

1.2 Block Diagram ............................................................................................3

1.3 Signal List ...................................................................................................4

1.4 External Components.................................................................................6

1.5 General Description....................................................................................7

1.5.1 Xtal Osc and Clock Dividers .......................................................7

1.5.2 Uncommitted Amplifier ...............................................................7

1.5.3 Tone/FSK Encoder and Tone Encoder ......................................7

1.5.4 SPM Generator ..........................................................................10

1.5.5 Transmit Operator .....................................................................10

1.5.6 Tx UART.....................................................................................10

1.5.7 ‘C-BUS’ Interface .......................................................................11

1.5.8 ‘C-BUS’ Registers......................................................................13

1.6 Application Notes .....................................................................................14

1.6.1 ‘Telecom Tones .........................................................................14

1.6.2 ‘C-BUS Timing...........................................................................17

1.7 Performance Specification.......................................................................21

1.7.1 Electrical Performance..............................................................21

1.7.2 Packaging ..................................................................................25