LM1971
www.ti.com
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
audio attenuator fabricated on a CMOS process.
Attenuation is variable in 1 dB steps from 0 dB to −62
dB. A mute function disconnects the input from the
output, providing over 100 dB of attenuation.
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3-Wire Serial Interface
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Mute Function
Click and Pop Free Attenuation Changes
8-Pin Plastic PDIP and SOIC Packages
Available
The performance of the device is exhibited by its
ability to change attenuation levels without audible
clicks or pops. In addition, the LM1971 features a low
Total Harmonic Distortion (THD) of 0.0008%, and a
Dynamic Range of 115 dB, making it suitable for
digital audio needs. The LM1971 is available in both
8-pin plastic PDIP or SOIC packages.
APPLICATIONS
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Communication Systems
Cellular Phones and Pagers
Personal Computer Audio Control
Electronic Music (MIDI)
The LM1971 is controlled by a TTL/CMOS compatible
3-wire serial digital interface. The active low LOAD
line enables the data input registers while the CLOCK
line provides system timing. Its DATA pin receives
serial data on the rising edge of each CLOCK pulse,
allowing the desired attenuation setting to be
selected.
Sound Reinforcement Systems
Audio Mixing Automation
KEY SPECIFICATIONS
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Total Harmonic Distortion 0.0008 % (Typ)
Frequency Response > 200 kHz (−3 dB) (Typ)
Attenuation Range (Excluding Mute) 62 dB
(Typ)
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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.
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.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 1995–2013, Texas Instruments Incorporated