LM1971M - Digitally Controlled Single Channel Audio Attenuator

Overview

The LM1971M is a high-performance, digitally controlled single-channel audio attenuator fabricated using a CMOS process. Designed for precision audio applications, this component provides variable attenuation in 1 dB steps from 0 dB to −62 dB, along with a mute function that disconnects the input from the output, offering over 100 dB of isolation. With its low Total Harmonic Distortion (THD) of 0.0008% and an impressive Dynamic Range of 115 dB, the LM1971M is ideal for demanding digital audio systems.

Features

• Precision Attenuation: Adjustable in 1 dB steps from 0 dB to −62 dB.
• Mute Function: Provides over 100 dB of input-to-output isolation when activated.
• Low Distortion: Total Harmonic Distortion (THD) as low as 0.0008% ensures high-fidelity audio output.
• Wide Dynamic Range: 115 dB dynamic range for superior audio performance.
• CMOS Technology: Fabricated on a CMOS process for low power consumption and high reliability.
• Digital Control: Easy integration with digital control systems for seamless operation.
• Single-Channel Operation: Designed for single-channel audio applications.
• Robust Performance: Suitable for professional and consumer audio equipment.

Applications

The LM1971M is versatile and can be used in a variety of audio applications, including:

• Professional Audio Equipment: Mixers, amplifiers, and audio processors.
• Consumer Electronics: High-end audio systems, home theaters, and soundbars.
• Digital Audio Workstations (DAWs): Precision volume control in recording and playback systems.
• Broadcast Equipment: Studio-grade audio attenuators for radio and television.
• Automotive Audio Systems: Premium in-car entertainment systems requiring low distortion.
• Telecommunications: Voice processing and audio routing systems.

Electrical Characteristics

The following table summarizes the key electrical characteristics of the LM1971M under typical operating conditions (unless otherwise specified):

Absolute Maximum Ratings

• Supply Voltage (V+): +7V
• Supply Voltage (V-): -7V
• Digital Input Voltage: -0.3V to V+ +0.3V
• Operating Temperature Range: -40°C to +85°C
• Storage Temperature Range: -65°C to +150°C

Operating Characteristics (TA = 25°C, V+ = +5V, V- = -5V)

• Attenuation Range: 0 dB to -62 dB (1 dB steps)
• Total Harmonic Distortion (THD): 0.0008% (typical) at 1 kHz, 0 dB attenuation
• Dynamic Range: 115 dB (typical)
• Signal-to-Noise Ratio (SNR): >110 dB
• Channel Separation: >100 dB
• Power Supply Rejection Ratio (PSRR): >80 dB
• Input Impedance: 20 kΩ (typical)
• Output Impedance: 100 Ω (typical)

Package Information

The LM1971M is available in a compact and industry-standard package, ensuring ease of integration into various circuit designs.

Package Type: SOIC-16

• Package Dimensions: 9.9 mm x 3.9 mm x 1.75 mm (body)
• Pin Count: 16
• Lead Pitch: 1.27 mm
• Mounting Style: Surface Mount
• Operating Temperature: -40°C to +85°C
• Moisture Sensitivity Level (MSL): MSL 1 (Unlimited Floor Life)

Pin Configuration

• Pin 1: Mute Control Input
• Pin 2: Digital Control Input (LSB)
• Pin 3-6: Digital Control Inputs
• Pin 7: Ground (GND)
• Pin 8: Negative Supply Voltage (V-)
• Pin 9: Audio Output
• Pin 10: Audio Input
• Pin 11-14: Not Connected (NC)
• Pin 15: Positive Supply Voltage (V+)
• Pin 16: Chip Select Input

Conclusion

The LM1971M is a high-precision, digitally controlled audio attenuator that delivers exceptional performance for both professional and consumer audio applications. With its low distortion, wide dynamic range, and flexible digital control, it is an excellent choice for designers seeking reliable and high-fidelity audio attenuation. Its compact SOIC-16 package ensures easy integration into a wide range of electronic systems, making it a versatile component for modern audio engineering.