LM1971

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SNAS104B – FEBRUARY 1995 – REVISED APRIL 2013

LM1971 Overture™ Audio Attenuator Series Digitally Controlled 62 dB Audio Attenuator

with/Mute

Check for Samples: LM1971

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FEATURES

DESCRIPTION

The LM1971 is a digitally controlled single channel

23

•

3-Wire Serial Interface

audio attenuator fabricated on a CMOS process.

•

Mute Function

Attenuation is variable in 1 dB steps from 0 dB to

−62

•

Click and Pop Free Attenuation Changes

dB. A mute function disconnects the input from the

output, providing over 100 dB of attenuation.

•

8-Pin Plastic PDIP and SOIC Packages

Available

The performance of the device is exhibited by its

ability to change attenuation levels without audible

APPLICATIONS

clicks or pops. In addition, the LM1971 features a low

Total Harmonic Distortion (THD) of 0.0008%, and a

•

Communication Systems

Dynamic Range of 115 dB, making it suitable for

•

Cellular Phones and Pagers

digital audio needs. The LM1971 is available in both

•

Personal Computer Audio Control

8-pin plastic PDIP or SOIC packages.

•

Electronic Music (MIDI)

The LM1971 is controlled by a TTL/CMOS compatible

3-wire serial digital interface. The active low LOAD

•

Sound Reinforcement Systems

line enables the data input registers while the CLOCK

•

Audio Mixing Automation

line provides system timing. Its DATA pin receives

serial data on the rising edge of each CLOCK pulse,

KEY SPECIFICATIONS

allowing

the

desired

attenuation

setting

to

be

selected.

•

Total Harmonic Distortion 0.0008 % (Typ)

•

Frequency Response > 200 kHz (

−3 dB) (Typ)

•

Attenuation Range (Excluding Mute) 62 dB

(Typ)

•

Dynamic Range 115 dB (Typ)

•

Mute Attenuation 102 dB (Typ)

Typical Application

Figure 1. Typical Audio Attenuator Application Circuit

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Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

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Overture is a trademark of dcl_owner.

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All other trademarks are the property of their respective owners.

PRODUCTION DATA information is current as of publication date.

Copyright © 1995–2013, Texas Instruments Incorporated

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.