LM1972 Datasheet | Texas Instruments

FEATURES - 2 3-Wire Serial Interface - Daisy-Chain Capability - 104d B Mute Attenuation - Pop and Click Free Attenuation Changes APPLICATIONS - Automated Studio Mixing Consoles - Music Reproduction Systems - Sound Reinforcement Systems - Electronic Music (MIDI) - Personal puter Audio Control KEY SPECIFICATIONS - Total Harmonic Distortion + Noise: 0.003 % (max) - Frequency response: 100 k Hz (- 3d B) (min) - Attenuation range (excluding mute): 78 d B (typ) - Differential attenuation: ±0.25 d B (max) - Signal-to-noise ratio (ref. 4 Vrms): 110 d B (min) - Channel separation: 100 d B (min) DESCRIPTION The LM1972 is a digitally controlled 2-channel 78d B audio attenuator fabricated on a CMOS process. Each channel has attenuation steps of 0.5d B from 0d B- 47.5d B, 1.0d B steps from 48d B- 78d B, with a mute function attenuating 104d B. Its logarithmic attenuation curve can be customized through software to fit the desired application. The performance of a μPot is demonstrated through its excellent 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 96d B. Transitions between any attenuation settings are pop free. The LM1972's 3-wire serial digital interface is TTL and CMOS patible; receiving data that selects a channel and the desired attenuation level. The Data Out pin of the LM1972 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 Connection Diagram Figure 1. Typical Audio Attenuator Application Circuit Figure 2. 20-Lead SOIC - Top View See DW Package 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. All trademarks are the property of their respective...