TLH7876

April 1987

LM1112ALM1112BLM1112C

Dolby

B-Type Noise Reduction Processor

General Description

The LM1112 is a monolithic integrated circuit specifically

designed to realize the Dolby B-type noise reduction sys-

tem

It is a replacement for the LM1111 and the Signetics NE-

645648 but with improved performance figures

Features

Y

Very high signalnoise ratio 74 dB encode

(CCIRARM)

Y

Wide supply voltage range 6V to 20V

Y

Very close matching to standard Dolby characteristics

Y

Audible switch-on transients greatly reduced

Y

Improved temperature performance

Y

Reduced number of precision external components

Y

Improved transient stability

Y

Input protection diodes

Available only to licensees of Dolby Laboratories Licensing Corporation San Francisco from whom licensing and application information must be obtained

Dolby and the double-D symbol are registered trademarks of Dolby Laboratories Licensing Corporation

Schematic Diagram

TLH7876 – 1

C1995 National Semiconductor Corporation

RRD-B30M115Printed in U S A