LM1973M National Semiconductor, LM1973M Datasheet

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LM1973M

Manufacturer Part Number
LM1973M
Description
Audio Power Amplifier IC
Manufacturer
National Semiconductor
Datasheet

Specifications of LM1973M

No. Of Pins
20
Peak Reflow Compatible (260 C)
No
Leaded Process Compatible
No
Mounting Type
Surface Mount
Package / Case
20-WSOIC
Lead Free Status / RoHS Status
Contains lead / RoHS non-compliant

Available stocks

Company
Part Number
Manufacturer
Quantity
Price
Part Number:
LM1973M
Manufacturer:
NS
Quantity:
505
Part Number:
LM1973M
Manufacturer:
NS/国半
Quantity:
20 000
Part Number:
LM1973MX
Manufacturer:
NS/国半
Quantity:
20 000
© 1999 National Semiconductor Corporation
LM1973
µPot
General Description
The LM1973 is a digitally controlled 3-channel 76dB audio
attenuator fabricated on a CMOS process. Each channel
has attenuation steps of 0.5dB from 0dB–15.5dB, 1.0dB
steps from 16dB–47dB, and 2.0dB steps from 48dB– 76dB,
with a mute function attenuating 104dB. Its logarithmic at-
tenuation curve can be customized through software to fit
the desired application.
The performance of a µPot
cellent Signal-to-Noise Ratio, extremely low (THD+N), and
high channel separation. Each µPot contains a mute function
that disconnects the input signal from the output, providing a
minimum attenuation of 96dB. Transitions between any at-
tenuation settings are pop free.
The LM1973’s 3-wire serial digital interface is TTL and
CMOS compatible; receiving data that selects a channel and
the desired attenuation level. The Data-Out pin of the
LM1973 allows multiple µPots to be daisy-chained together,
reducing the number of enable and data lines to be routed
for a given application.
Typical Application
µPot
and Overture
FIGURE 1. Typical Audio Attenuator
3-Channel 76dB Audio Attenuator with Mute
are trademarks of National Semiconductor Corporation.
Application Circuit
is demonstrated through its ex-
DS011958
DS011958-1
Key Specifications
n Total Harmonic Distortion + Noise:
n Frequency response:
n Attenuation range (excluding mute):
n Differential attenuation:
n Signal-to-noise ratio (ref. 4 Vrms):
n Channel separation:
Features
n 3-wire serial interface
n Daisy-chain capability
n 104dB mute attenuation
n Pop and click free attenuation changes
Applications
n Automated studio mixing consoles
n Music reproduction systems
n Sound reinforcement systems
n Electronic music (MIDI)
n Personal computer audio control
Connection Diagram
See NS Package Number M20B or N20A
Order Number LM1973M or LM1973N
Surface Mount Package
Dual-In-Line Plastic or
Top View
100 kHz (−3dB) (min)
December 1994
DS011958-2
±
0.003% (max)
0.25dB (max)
www.national.com
110dB (min)
110dB (typ)
76dB (typ)

Related parts for LM1973M

LM1973M Summary of contents

Page 1

... Sound reinforcement systems n Electronic music (MIDI) n Personal computer audio control Connection Diagram Dual-In-Line Plastic or Surface Mount Package DS011958-1 Top View Order Number LM1973M or LM1973N See NS Package Number M20B or N20A December 1994 0.003% (max) 100 kHz (−3dB) (min) 76dB (typ) ± 0.25dB (max) ...

Page 2

... Absolute Maximum Ratings If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Supply Voltage (V – Voltage at Any Pin V − 0. Power Dissipation (Note 3) ESD Susceptability (Note 4) Junction Temperature Electrical Characteristics The following specifications apply for all channels with V = 25˚ ...

Page 3

Electrical Characteristics (Notes 1, 2) (Continued) Pin Description Signal Ground (1, 5, 17): Each input has its own indepen- dent ground, GND1, GND2, and GND3. Signal Input (2, 4, 18): There are 3 independent signal in- puts, IN1, IN2, and ...

Page 4

Typical Performance Characteristics Supply Current vs Supply Voltage DS011958-16 THD vs Freq by FFT = 12V V − DS011958-19 THD + N vs Frequency and Amplitude DS011958-22 www.national.com Supply Current vs Temperature DS011958-17 THD ...

Page 5

Typical Performance Characteristics THD + N vs Amplitude ± Hz into CH1 DS011958-25 Application Information ATTENUATION STEP SCHEME The fundamental attenuation step scheme for the LM1973 µPot is ...

Page 6

Application Information LM1973 Channel Attenuation vs Digital Step Value (Programmed 2.0dB Steps) FIGURE 5. LM1973 2.0dB Attenuation Step Scheme FIGURE 6. Mono Level Control with Panning Circuit INPUT IMPEDANCE The input impedance of a µPot is constant at a nominal ...

Page 7

Application Information (Continued) FIGURE 7. Serial Data Format Transfer Process TABLE 1. LM1973 Micropot Attenuator Register Set Description MSB: LSB Address Register (Byte 0) 0000 0000 Channel 1 0000 0001 Channel 2 0000 0010 Channel 3 Data Register (Byte 1) ...

Page 8

Application Information DAISY-CHAIN CAPABILITY Since the µPot’s digital interface is essentially a shift register, multiple µPots can be programmed utilizing the same data and load/shift lines. As shown in Figure 11 , for an n-µPot daisy-chain, there are 16n bits ...

Page 9

Application Information (Continued) FIGURE 10. Digitally-Controlled Logarithmic Gain Amplifier Circuit FIGURE 11. n-µPot Daisy-Chained Circuit DS011958-13 9 DS011958-12 www.national.com ...

Page 10

... Physical Dimensions inches (millimeters) unless otherwise noted www.national.com Surface Mount Package Order Number LM1973M NS Package Number M20B Dual-In-Line Plastic Package Order Number LM1973N NS Package Number N20A 10 ...

Page 11

... NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant ...

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