LM1972 - Micro-Pot 2-Channel 78 dB Audio Attenuator with Mute

The LM1972 is a digitally controlled 2-channel 78dB audio attenuator fabricated on a CMOS process. Each channel has attenuation steps of 0.5dB from 0dB–47.5dB, 1.0dB steps from 48dB–78dB, with a mute function attenuating 104dB. 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 96dB. Transitions between any attenuation settings are pop free.

The LM1972'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 LM1972 allows multiple μPots to be daisy-chained together, reducing the number of enable and data lines to be routed for a given application.

Products containing the "LM1972" keyword are: LM1972 , LM1972M , LM1972M , LM1972M/NOPB , LM1972M/NOPB , LM1972M5 , LM1972MNOPB , LM1972MX , LM1972MX/NOPB , LM1972MX/NOPB , LM1972MXNOPB , LM1972N

• 3-Wire Serial Interface
• Daisy-Chain Capability
• 104dB Mute Attenuation
• Pop and Click Free Attenuation Changes

Key Specifications

• Total Harmonic Distortion +
  Noise: 0.003 % (max)
• Frequency response: 100 kHz (−3dB) (min)
• Attenuation range (excluding
  mute): 78 dB (typ)
• Differential attenuation: ±0.25 dB (max)
• Signal-to-noise ratio
  (ref. 4 Vrms): 110 dB (min)
• Channel separation: 100 dB (min)

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