Data Sheet
March 1997
L7554 Low-Power SLIC
Content
Table of Contents
Page
Features .................................................................................................................................................................. 1
Description ............................................................................................................................................................... 1
Pin Information ......................................................................................................................................................... 4
Functional Description.............................................................................................................................................. 6
Absolute Maximum Ratings ..................................................................................................................................... 6
Recommended Operating Conditions ..................................................................................................................... 7
Electrical Characteristics ......................................................................................................................................... 7
Ring Trip Requirements..................................................................................................................................... 11
Test Configurations ............................................................................................................................................... 12
Applications ........................................................................................................................................................... 14
Design Considerations ....................................................................................................................................... 16
Characteristic Curves......................................................................................................................................... 17
dc Applications ................................................................................................................................................... 20
Battery Feed.................................................................................................................................................... 20
Overhead Voltage .......................................................................................................................................... 20
Adjusting Overhead Voltage ........................................................................................................................... 21
Adjusting dc Feed Resistance......................................................................................................................... 22
Adjusting Overhead Voltage and dc Feed Resistance Simultaneously .......................................................... 22
Loop Range..................................................................................................................................................... 22
Off-Hook Detection ......................................................................................................................................... 22
Ring Trip Detection......................................................................................................................................... 23
Ring Ground Detection................................................................................................................................... 23
ac Design ........................................................................................................................................................... 24
First-Generation Codecs.................................................................................................................................. 24
Second-Generation Codecs ............................................................................................................................ 24
Third-Generation Codecs ................................................................................................................................ 24
Selection Criteria ............................................................................................................................................. 24
PCB Layout Information ......................................................................................................................................... 26
Outline Diagram...................................................................................................................................................... 27
44-Pin PLCC....................................................................................................................................................... 27
Ordering Information........................................................................................................................................... 28
2
Lucent Technologies Inc.
AGERE [ AGERE SYSTEMS ]
